Image source, Getty Images

The editor-in-chief of Russia's Novaya Gazeta newspaper - an outlet critical of the Kremlin - has pledged to donate his Nobel Peace Prize medal to raise funds for Ukrainian refugees.

Dmitry Muratov said in an article on Tuesday that his decision was prompted by the displacement of 10 million Ukrainians from their homes amid the Russian invasion.

"I ask the auction houses to respond and put up for auction this world-famous award," he wrote of the gong he won last year.

Hugo Bachega and Orysia Khimiak
BBC News in Lviv, Ukraine

Image source, Ukrainian Interior Ministry via Getty

The aftermath of a bomb hitting a Ukrainian theatre, where hundreds of people were hiding, was "terrible" and "heartbreaking", says 27-year-old locksmith Vladyslav.

The BBC has spoken to survivors who described for the first time what happened when the bomb fell on the building in the besieged south-eastern city Mariupol.

Vladyslav, who does not want us to use his full name, was near the main entrance when the explosion hit.

He ran with others into a basement and, 10 minutes later, heard the building was on fire and emerged to a scene of chaos.

"One mother was trying to find her kids under the rubble", he says.

"Terrible things were happening."

Read more about Vladyslav's experiences here.

Russian forces have not staged any large assaults this week, and have been digging in and reinforcing defensive positions, according to the latest assessment from the Institute for the Study of War.

The think tank's assessment echoes what we heard from the American Department of Defense on Tuesday, which said that Russian troops remain bogged down by logistical difficulties.

The Kremlin continues to downplay the effect of sanctions on the Russian economy, the think tank's authors state.

Meanwhile, Russian shelling on civilian regions has continued and intensified.

Image source, Ukrainian government

Ukrainian President Volodymr Zelensky says about 100,000 people remain in the southern port city of Mariupol amid intense Russian bombardment.

"As of today, there are about 100,000 people in the city. In inhumane conditions. In a complete blockade. No food, no water, no medicine. Under constant shelling, under constant bombing," he said in his nightly Facebook address.

He added that efforts to rescue civilians there through humanitarian corridors have been interrupted by Russian "shelling or deliberate terror".

One humanitarian column was captured by Russia on Tuesday, he said, adding that Ukrainian government workers and their bus driver had been taken prisoner.

"Despite all the difficulties," he says, "7,026 Mariupol residents were rescued" from the city on Tuesday.

Zelensky added that Ukraine has received over 100,000 tonnes in humanitarian aid in the past two weeks.

He said new Western sanctions would be unveiled against Russia this week when world leaders attend a Nato conference in Brussels.

Zelensky also said he had spoken to Pope Francis on Tuesday, and invited him to visit Ukraine.

"I believe that we will be able to organise this important visit, which will unequivocally support each of us, each of the Ukrainians," he said.

Image source, Getty Images

Ukrainian cities under Russian occupation continue to see civilian-led protests, according to the latest intelligence assessment, external from the UK Ministry of Defence.

"Russian efforts to subdue the population by manipulating the media, spreading propaganda and installing puppet, pro-Kremlin, leaders have so far failed," the report says.

It adds that Russia "will probably respond to these failure by increasingly violent and coercive measures" to suppress the Ukrainian people.

Lucy Manning
BBC News Special Correspondent

Image source, Mariia

Families in the UK desperate to give a home to Ukrainians in need have spoken of their frustration and sadness at a process they say is too slow and bureaucratic.

One described "hours and hours and hours" of form filling, while a British businessman who is in Poland to bring a family back to England says it's taking a long time and must be quicker.

There has been an enormous groundswell of support for hosting Ukrainian refugees in homes across the UK.

In Marlow, Buckinghamshire, Rebecca Lewis is hoping to emulate her grandfather who helped families fleeing Germany in World War Two.

She has helped to organise 30 homes for Ukrainian refugees, but so far they have received no refugees.

Rebecca describes having to search on Facebook through heartbreaking posts of Ukrainian families pleading for help and homes.

"Tidy with no bad habits," says one. Another says, "I have to leave the country because I have no other way to save my life", and "I can work and want to find a job after coming to you"

Read more from Lucy here.

Image source, Getty Images

Comments made by Putin spokesman Dmitry Peskov in a CNN interview on Tuesday - in which he did not rule out the potential use of Russian nuclear weapons - should not be interpreted as a change in the country's nuclear policy, experts say.

As we reported earlier, Peskov said that nuclear weapons would only be used within the "concept of domestic security," and if Russia was facing an "existential threat". He pointed to the country's publicly available policy, outlining when nuclear weapons can be used.

"This is a restatement of long-standing doctrine, not a new thing," tweeted Matt Tait, external, former principal security consultant for iSEC Partners and NGS Secure.

"Don't get me wrong, they enjoy the US panicking about their nuclear weapons, but this is a statement divorced from a change of posture," he added.

Image source, EPA

German Chancellor Olaf Scholz has said Europe's sanctions on Russia could be "not a short-term measure but a longer conflict".

He emphasised the need for Germany to stop its dependency on Russian coal, gas and oil imports "as quickly as possible" and "in the greatest intensity" during a press conference in Berlin.

"Europe, together with its friends, has launched the harshest sanctions ever seen against such a big country. And they show that they have an impact," he said.

"A part of this is also thinking about tools that have this effect on the aggressor but at the same time have minimal repercussions on economic development opportunities at home and that we can uphold these sanctions."

Image source, Getty Images

Ukrainian President Volodymr Zelensky will deliver a virtual address to the Nato summit of world leaders being held in Brussels on Thursday, according to the AFP news agency.

"President Zelensky is invited to address the Nato summit via video link," an unnamed Nato official told AFP.

"This will be an opportunity for allied leaders to hear directly from President Zelensky about the dire situation facing the people of Ukraine because of Russia's aggression."

A spokesman for Zelensky told Interfax Ukraine that the president would be appearing in video format at some point during the conference, but that the details are still being worked out.

"Ukraine will take an active part in it... At the least, it will be the president's address. At most - full participation, of course, in video format."

"The format of participation will be known in the coming days," spokesman Serhiy Nikiforov said on Tuesday.

Image source, Getty Images

The French government has confirmed that President Emmanuel Macron spoke to Russian President Vladimir Putin in a phone call on Tuesday.

In a statement, the Elysée Palace said that the call continued Macron's previous conversations with Putin regarding a ceasefire and ongoing safety concerns.

"There is currently no agreement but President Macron remains convinced of the need to continue his efforts. There is no other way out than a ceasefire and Russia's good faith negotiations with Ukraine," the statement said.

It added that Macron "stands alongside Ukraine".

In addition to Putin, Macron also spoke on Tuesday to German Chancellor Olaf Scholz and Italian Prime Minister Mario Draghi ahead of the summit in Brussels on Thursday.

The call was held to discuss European energy needs in light of the war in Ukraine, as well as food security concerns.

Hugo Bachega and Orysia Khimiak
BBC News in Lviv, Ukraine

Image source, ANADOLU AGENCY / GETTY IMAGES

Hundreds of civilians, mostly women and children, went to hide in a theatre in the besieged city Mariupol - one of them, 27-year-old teacher Mariia Rodionova, has told the BBC of her survival after a bomb hit the building.

Mariia had been living in this grand Soviet-era building near the waterfront for 10 days, having fled her 9th-floor apartment with her two dogs.

Last Wednesday, a bomb hit and - within seconds - the building had been split in two and left in ruins.

It is unclear how many people died, but Mariia says the blast was so loud that she thought her eardrum must have split.

Read more about Mariia's experiences here.

Image source, Reuters

Kremlin spokesman Dmitry Peskov has said Russia would only use nuclear weapons if the country faced an existential threat.

Asked by CNN if President Putin would consider using nuclear weapons, Peskov said: "We have a concept of domestic security and it's public, you can read all the reasons for nuclear arms to be used.

"So if it is an existential threat for our country, then it [the nuclear arsenal] can be used in accordance with our concept."

Russian President Vladimir Putin said on 28 February, just days after Russia invaded Ukraine, that he was putting Russia's strategic nuclear forces on special alert.

Read more from the BBC's Russia Editor Steve Rosenberg: Would Putin press the nuclear button?

Reality Check

Image source, YAŞAR ANTER

Two superyachts linked to Russian billionaire Roman Abramovich have docked in Turkey, beyond the reach of UK and EU sanctions.

Each of the vessels cost more than $500m (£377m) and are among a number tracked by Lloyd's List Intelligence.

The shipping data experts have been monitoring on-board tracking devices and have shared this information exclusively with the BBC, enabling the journeys of these and other vessels linked to sanctioned Russians to be plotted.

A boatload of young Ukrainians tried to stop the superyacht My Solaris docking in Bodrum in Turkey. The other Abramovich-linked yacht Eclipse sailed to Marmaris.

Many superyachts are linked to Russian billionaires but ownership is shrouded in secrecy - boats are often registered through a series of offshore companies.

Read more.

Image source, Getty Images

As we reported earlier, US President Joe Biden plans to announce a new sanctions package against Russia during his trip to Brussels and Warsaw this week.

Biden will visit the Belgian capital, where Nato and the European Union have their headquarters, to hold talks with foreign leaders on Thursday. He will be accompanied by the US Secretary of Defence, General Lloyd Austin.

He will then travel to Warsaw, the capital of Poland, on Friday.

"He will have the opportunity to co-ordinate on the next phase of military assistance to Ukraine," Jake Sullivan, the US national security adviser, told reporters.

Biden, he added, "will join our partners in imposing further sanctions on Russia and tightening the existing sanctions to crack down on evasion and to ensure robust enforcement".

Earlier on Tuesday, Mr Biden's top spokeswoman Jen Psaki announced that she would be forced to skip the European tour after testing positive for Covid. She said that she had held two socially distanced meetings with Biden on Monday, and that he had tested negative on Tuesday.

Russian forces initially made rapid gains in the south of Ukraine, with their main objective being the creation of a land corridor between Crimea, which it annexed in 2014, and areas held by Russian-backed separatists in Donetsk and Luhansk.

Standing in the way of that objective is the port city of Mariupol, which has been encircled by Russian forces since the start of March. Ukrainian officials say some 300,000 civilians remain trapped in the city.

See more maps showing the war in Ukraine here.

Image source, Reuters

Ukraine earlier renewed its appeal for humanitarian aid to be allowed into the besieged port city of Mariupol and for civilians to be allowed to leave.

Residents of Mariupol, a key strategic target for Moscow, have endured weeks of Russian bombardment with no power or running water.

Ukraine has previously accused Russian forces of bombing a theatre where civilians were sheltering in Mariupol.

Speaking on Ukrainian television, Ukraine's Deputy Prime Minister, Iryna Vereshchuk, said: "We demand the opening of a humanitarian corridor for civilians."

Vereshchuk also said Russia's armed forces were preventing humanitarian supplies reaching residents of the southern city of Kherson.

Russia has repeatedly denied targeting civilians since invading Ukraine.

Russian media are reporting that Vladimir Putin has spoken to the French President Emmanuel Macron by phone.

The conversation was initiated by France, the Ria Novosti state-owned news agency said. Interfax news agency said the call saw the two leaders discuss peace talks between Russia and Ukraine.

There has been no confirmation from the French government of this, but the two leaders have held several lengthy phone calls both before and since the Russian invasion of Ukraine.

Andrew Harding
BBC News, Voznesensk

Image source, BBC.

A ferocious two-day struggle for control of the farming town of Voznesensk and its strategically important bridge was one of the most decisive battles of the war in Ukraine so far.

Victory would have enabled Russian forces to sweep further west along the Black Sea coast towards the huge port of Odesa and a major nuclear power plant.

Instead, Ukrainian troops, supported by an eclectic army of local volunteers, delivered a crushing blow to Russian plans, first by blowing up the bridge and then by driving the invading army back, up to 100km, to the east.

"It's hard to explain how we did it. It's thanks to the fighting spirit of our local people and to the Ukrainian army", said Voznesensk's 32-year-old mayor, Yevheni Velichko.

As on so many frontlines in Ukraine, British-supplied anti-tank missiles proved crucial in turning the tide against Russian armour in Voznesensk, leaving the town littered with up to 30 tanks, armoured cars and even a helicopter.

"It's only thanks to these weapons that we were able to beat our enemy here", said Mr Velichko.

Read more about the remarkable Ukrainian victory in Voznesensk here.

Image source, Reuters

The US national security adviser Jake Sullivan has said there will be "hard days" ahead in Ukraine.

Sullivan has been speaking to reporters at the White House ahead of President Joe Biden's trip to Brussels on Wednesday.

The US and allies will roll out a further package of sanctions against Russia on Thursday when the president holds talks, Sullivan said.

Sullivan also said that the US has not seen any evidence of China providing Russia with weapons.

From Brussels, Biden will travel on to Warsaw in Poland, which borders Ukraine and is a Nato member.

Image source, Getty Images

Ten million people have now fled their homes in Ukraine because of the Russian invasion, the United Nations High Commissioner for Refugees says.

As of 21 March, 3.5 million people are estimated to have left for neighbouring countries, while 6.5 million people are thought to be displaced inside the war-torn country itself.

The UN estimates:

• Poland has taken in 2,113,554 refugees
• Romania 543,308
• Moldova 367,913
• Hungary 317,863
• Slovakia 253,592
• Russia 252,376
• Belarus 4,308

Read more here.