We have more now on how the talks between Russian and Ukrainian negotiators are going.

In a video posted on social media, President Zelensky's adviser, Mykhailo Podolyak, said Russia was beginning to engage constructively.

"Russia now much more adequately perceives the world around it. It is much more sensitive to the position of Ukraine, which has been proven in battlefields, and in Ukraine's actions in terms of protecting its interests.

"Our proposals are on the table, and they are very tough. First of all, they concern the withdrawal of troops, the ceasefire, and so on. In principle, we will not give up any of our positions. Russia already understands this. Russia is starting to talk constructively."

Even the senior US diplomat, Wendy Sherman, said Russia was showing signs of engaging in substantive negotiations, says the BBC's diplomatic correspondent James Landale.

But neither side would say where progress, if any, had been made, on humanitarian issues or even the possibility of a ceasefire, our correspondent adds.

France’s Foreign Minister, Jean-Yves Le Drian, struck a more pessimistic note, telling French radio the war would be long and “the worst was ahead of us”.

Image source, Getty Images

Sherlock star - and Oscar contender - Benedict Cumberbatch has intimated he is considering hosting a Ukrainian refugee.

Earlier today, Housing Secretary Michael Gove launched the Homes for Ukraine scheme, calling on British households to offer a room - or spare flat - to a nominated individual or family fleeing the Russian invasion of Ukraine.

Speaking on the red carpet, ahead of Sunday's Bafta film awards, Cumberbatch - who was wearing a badge with the colours of the Ukrainian flag - said he hoped to take in a refugee.

"What we all have to do is continue to put pressure on our politicians as far as the refugee crisis goes, continue to put pressure on the Putin regime, continue to help in any which way we can - whether that's through donations or housing refugees, all of which I'm looking to do - and have done."

Among those trapped in Mariupol are a group of Turkish citizens currently sheltering in a mosque in the city, according to the Turkish government which has asked Russia to help evacuating them.

On Saturday Ukraine's foreign ministry said Russian forces had shelled the Sultan Suleiman mosque, where it said 86 Turks were sheltering, including 34 children.

On Sunday Turkish Foreign Minister Mevlut Cavusoglu said buses had been waiting to evacuate Turkish citizens "for some days" but had been hampered by ongoing fighting in the city.

Speaking at a news conference in Antalya, he said he had appealed to Russian Foreign Minister Sergei Lavrov for support with the evacuation and expected "to make some headway" on the matter.

Earlier attempts to evacuate people from Mariupol, where the humanitarian situation has become desperate, have collapsed - with the Ukrainians and Russians blaming each other.

Cavusoglu said 14,480 Turkish citizens had so far been evacuated from Ukraine.

The Red Cross has urged all parties in the Ukraine conflict to come to an agreement over humanitarian aid, warning "time is running out" in Mariupol.

“We call on all parties involved in the fighting to place humanitarian imperatives first," said Peter Maurer, president of the International Committee of the Red Cross.

"People in Mariupol have endured a weeks-long life-and-death nightmare. This needs to stop now. Their safety and their access to food, water and shelter must be guaranteed.”

Pensioners and children alike, as well as ICRC staff, are sheltering in unheated basements in Mariupol where dead bodies littered the city centre, said a statement by the ICRC - describing the human suffering in the port city as "immense".

The charity called for a "concrete, precise, actionable agreement" to be implemented "without delay" so civilians can reach safety - and urged military forces to respect the ceasefire and give residents time to leave.

It appealed to both sides "to respect international humanitarian law" and not to target civilian infrastructure, hospitals or medical personnel.

"History will look back at what is now happening in Mariupol with horror if no agreement is reached by the sides as quickly as possible," the statement concluded.

Image source, Getty Images

There have also been anti-war protests in Russia - where police detained more than 800 people on Sunday.

The OVD-Info NGO, which monitors arrests during protests, said police had detained 817 people during demonstrations in 37 cities in Russia.

Law enforcement in Moscow said they had detained approximately 300 people in the city centre for breaches of public order.

Image source, EPA

Earlier today up to 30,000 protesters waved Ukrainian flags and held anti-war banners at a big demonstration in central Berlin.

Image source, EPA

A lot of our reporting today has focused on the Yavoriv military base near Lviv, Irpin outside Kyiv where an American journalist was shot dead, and the desperate humanitarian situation in the south-eastern city of Mariupol.

But there are countless other towns with their own stories of what the war has brought.

One is Zhytomyr to the west of Kyiv - hit by more than 40 rocket and air attacks with dozens killed, both soldiers and civilians.

Mayor Serhiy Sukhomlyn says the town is a key logistics hub, with aid from Europe being delivered from there to Kyiv and beyond while refugees travel in the opposite direction.

Nina, a resident, told the BBC that her entire street of bungalows had been destroyed, with three people killed and many seriously injured.

She ran with her children to a neighbour's basement as soon as she heard the air raid siren.

“It sounded like the plane was very low, nearly touching us. The ground was shaking. How could they not see they are bombing residential areas?” Nina asked.

One of her neighbours, a mother-of-three, had been badly wounded in the head and stomach by flying glass, she said.

Nina has since left Zhytomyr and is heading to Poland, but her daughter has decided to stay in the city with her boyfriend, who was badly injured in the leg during the bombing.

Now the town is bracing for a possible ground offensive; the mayor meanwhile is working to ensure the remaining half of the local population still has access to basic services.

Image source, Russian Defence Ministry/Getty Images

Ukraine's atomic energy ministry says power has been restored to the Chernobyl nuclear plant, following warnings of the increased risk of a radiation leak if a high-voltage power line damaged in the fighting was not repaired.

Cooling systems are operating normally with no requirement for backup power, the atomic energy ministry said.

Russian forces seized the nuclear power plant - the site of the world's worst nuclear disaster - on the first day of the invasion last month.

Although no longer a working power station, Chernobyl was never fully abandoned and still requires constant management.

Concerns remain for the staff who remain at the power plant under the authority of Russian forces.

Workers continue to go about their duties and the atmosphere is said to be calm, but the BBC has been told that the conditions inside are difficult, with food and medicine limited.

Image source, Reuters

Ukraine's Deputy Prime Minister Iryna Vereshchuk has been giving an update on the evacuation of civilians inside the country and humanitarian corridors.

More than 140,000 civilians had been evacuated from conflict zones in the country, she said in an interview on national television.

On Sunday several thousand people had been evacuated from towns in the Kyiv region, and some 5,000 people had also been evacuated from the eastern Luhansk region, she added.

But she said a humanitarian convoy had once again failed to reach the besieged port city of Mariupol because of Russian shelling.

"The column has stayed in [the Russian-occupied city of] Berdiansk, and will tomorrow again attempt to reach Mariupol,” she is quoted as saying by Reuters news agency.

Image source, Submitted image

Some more hopeful news - a group of children who fled Poltava in central Ukraine have reached the west of the country.

The nearly 100 children and their care workers were helped by a British charity to make the "very difficult" 48-hour journey.

"On the way we met a bus that broke down with women and small children," the care workers wrote. "We decided to pick them up, we had to squeeze in a lot. There were even premature babies."

Ken Hart, chairman of charity The Epaphras Trust, which organised the evacuation, described the fund-raising efforts in the British city Bristol as "essential".

"They gathered money and helped to put fuel in their buses - and the buses took these children to a place of safety," he said.

Hints of progress at talks?published at 17:05 Greenwich Mean Time 13 March 2022

17:05 GMT 13 March 2022

Hugo Bachega
BBC News, Lviv

Are Russians and Ukrainians making progress in their talks about the war? We’ve been given some indications that maybe they are.

“I think that we’ll achieve some results literally in a matter of days,” Mykhailo Podolyak, a Ukrainian negotiator and adviser to President Volodymir Zelensky, said.

He cautioned, however, that Ukraine would not “concede in principle on any positions”.

“Russia now understands this. Russia is already beginning to talk constructively,” he added.

From Russia, Leonid Slutsky was quoted as saying: “According to my personal expectations, this progress may grow in the coming days into a joint position of both delegations, into documents for signing.”

The comments are a bit encrypted, and this can be seen as a sign of how difficult these negotiations are. And there was no detail on what exactly they’re talking about. Ceasefire? End of the war? And what exactly are their demands at the negotiation table?

Both sides have already held three rounds of talks in Belarus, which focused mainly on humanitarian issues.

It’s day 18 of the war. Thousands of civilians are in desperate need of aid. Dozens are still dying every day. A deal to end all of this couldn’t come soon enough.

Wietske Burema
BBC News, Kyiv

Image source, Wietske Burema

The mood in central Kyiv is one of deep apprehension.

During a sombre morning service at St Volodymyr's Cathedral I saw two Ukrainian soldiers standing among the congregation, dressed in camouflage uniforms and with blue tape around their arms.

About 15 to 20 emergency services personnel, in their blue uniforms, said prayers as they lit candles in front of icons. One of them said they had come to the cathedral especially because they did not know what was going to be happening in a week’s time.

With Russian troops advancing on the capital, everyone seems to be waiting for war to come.

As I walked down one street, a soldier asked me: “Why are you still here?”

I also saw a slim woman in a blue duffel coat, standing straight and stock still, carefully taking in the city. It was as if she wanted to drink in the moment - remembering the city as it now, beautiful and intact, and wondering whether it will still be there when she looks again.

Journalists will no longer be allowed to enter the town of Irpin, near Kyiv, the town's Mayor Oleksandr Markushyn has said on Telegram, following the death of American journalist Brent Renaud in the town earlier today.

"Starting today, we are banning journalists from entering Irpin. We want to save the lives of both them and our defenders," Markushyn said.

He also urged reporters and Ukrainian civilians not to post information online about military personnel, their equipment or anything that could indicate their location.

Russia's defence ministry is asserting that its missile attack on the Yavoriv training facility in western Ukraine killed "up to 180 foreign mercenaries" and destroyed a large amount of weapons supplied by outside nations.

Defence ministry spokesman Igor Konashenkov told a briefing Russia would continue its attacks against foreign fighters joining Ukrainian forces, Russian media report.

Ukrainian officials earlier said 35 people were killed and more than 130 wounded in the attack.

Hugo Bachega
BBC News, near Yavoriv military base

Day after day, Ukrainians have been urging Nato to impose a no-fly zone over the country, to prevent Russia from carrying out air strikes.

It’s a message we heard from almost every resident we talked to near the Yavoriv military base near the Polish border after the facility was hit by cruise missiles. At least 35 people have died, the worst attack in western Ukraine since the start of the Russian invasion.

Nadin Berezovska, a 39-year-old photographer, said: “It was very scary. We’re in shock. We ask Nato to close the sky… In Ukraine, there’s no place to hide... Now we realise that it doesn’t matter where you live.”

Yurii Vitiv, a 50-year-old driver, said: “We’re asking the European community and Nato to close the sky, we need it. Because right now, all they say is that they’re concerned and worried, but we require actions to save innocent lives.”

Nato, however, has been firm that a no-fly zone is not happening.

If you're just joining us, this morning saw a major Russian missile attack on a military facility in western Ukraine near the Polish border.

• Local officials said up to 30 missiles were fired at the International Center for Peacekeeping and Security in Yavoriv, although some were intercepted before they hit
• At least 35 people are known to have been killed and more than 130 suffered injuries
• The base lies just 10km (6.2miles) from the Polish border and is normally used for training and joint exercises by the Ukrainan military and its Nato partners
• The US says none of its personnel were on site at the time. A Nato official says no personnel from the alliance were there
• Reports suggest that since the war began the base has been used for training foreign fighters and for storing weapons shipped in from outside Ukraine
• The attack has seen Ukraine renew calls for a no-fly zone above the country, but Pentagon spokesman John Kirby again made it clear this would not happen. It would not make sense "for this war to be escalated between two nuclear powers", he said

Earlier this week, Russia made the unsupported claim that biological weapons were being developed in laboratories in Ukraine with support from the US.

This has been dismissed by Ukraine and the US as a "false flag" - a claim intended to justify Russia's possible use itself of a chemical weapon against cities in Ukraine.

Now a White House national security adviser has warned Russia that it would pay a "severe price" if it carried out a chemical weaponattack.

Jake Sullivan said the US and allies were consulting closely about the increased threat.

He added that any attack on the territory of a Nato member state - following this morning's missile strike on the Yavoriv base near the Polish border - would trigger a full response by the alliance.

Read more - Fact-checking Russia's biological weapons claims

As we've been reporting, American Brent Renaud is thought to have been the first foreign reporter killed in the Ukraine conflict.

But there has been at least one other journalist killed - a cameraman who died in the Kyiv TV tower attack.

Yevhenii Sakun, a correspondent and camera operator for the Ukrainian television channel LIVE who was also working for the Spanish news agency EFE, was killed during a strike on the tower on 1 March, the International Federation of Journalists says, external.

And several others have come under fire, including Swiss photographer Guillaume Briquet, who was shot at by presumed members of a Russian special commando shortly after he passed a checkpoint on a road towards the southern city of Mykolaiv on 6 March, Reporters Without Borders, external says.

Briquet says he was also harassed by the soldiers, who stole €3,000 ($3,275; £2,500) and reporting equipment from him.

Guy Delauney
BBC Balkans correspondent

Authorities in Croatia say it's still not clear who launched a military drone that crashed in capital Zagreb on Thursday.

Military investigators spent Saturday digging out what's left of the drone from the crater it caused in the city's Jarun district.

As they worked, students were evacuated from the dormitory which the unmanned aircraft narrowly missed when it came down.

The head of the military police said the drone's black box had been recovered intact.

That could help investigators pinpoint who fired it - and to what end. A Croatian military official confirmed that the drone was a Soviet-era TU-141.

Despite its age, it's still being used by the Ukrainian military. But officials in Kyiv have denied responsibility for the incident.

There's been widespread alarm in Croatia that a military drone could have reached Zagreb from Ukraine without being intercepted.

Prime Minister Andrej Plenkovic has criticised the lack of reaction from Nato - and called for closer co-operation between member states.

Image source, EPA

Fergal Keane
BBC News, Lviv

Since the war began, hundreds of thousands of people have passed through Lviv train station in the west of Ukraine, just 40 miles (64km) from the Polish border. It has become a refuge for those fleeing the fighting.

The train drivers are key to keeping the station running – often putting themselves at risk to transport Ukrainians long distances across the country to safety. Boris Lysenko is one of them, driving the crucial route from capital Kyiv to Lviv and back.

He is brave but modest with it: "Saving people is our duty. My duty is safe travel and transporting people on time."

He says he is not scared, but he does worry for his wife and son, who have remained in Kyiv: "We hope for better times, Ukraine will win and everything will [be] good."

Watch Boris’ story and meet the passengers trying to escape the war in Platform 5: Escaping Ukraine with Fergal Keane on iPlayer (UK only) and on BBC World News at 18:30 and 23:30 GMT on Sunday.