And another line from the Ukrainian president: after days of shelling in Ukraine's cities, Zelensky vows that the country will be rebuilt - and says Russia will learn about "reparations".

"Even if you destroy all our Ukrainian cathedrals and churches, you will not destroy our faith, our sincere belief in Ukraine and God, belief in people," he says.

"We will rebuild every single house, every single street, every single city."

"And we are telling Russia - learn the words 'reparations' and 'contributions'. You will pay back fully to us for what you've done against our state, against our every single Ukrainian."

And here's more from Ukrainian President Zelensky's latest video update.

He refers directly to Vladimir Putin, telling the Russian president to: "Go home. To your home."

He says Putin should defend the Russian-speaking people - not around the whole world - "but in your home".

"There are quite a few of them there too. About 150 million."

This appears to be a reference to Moscow's claim that their action is in defence of Russian-speaking people in parts of Ukraine.

Zelensky also likens Russia's invasion to a virus, saying it has been two years since Ukraine recorded its first Covid case: "It's been a week now that another virus attacked."

The most dangerous moments still lie aheadpublished at 10:03 Greenwich Mean Time 3 March 2022

10:03 GMT 3 March 2022

Fergal Keane
BBC News, Lviv

The most dangerous moments of this conflict are ahead. The Russian advance is going slower and meeting far greater resistance than President Putin expected. There are severe problems of logistics, command, morale and fighting effectiveness. But the Russians will grind on. As they do the civilian casualties in areas hit by shelling will mount.

While Western sanctions and boycotts have shown a rare degree of unanimity they will take time to have an effect. They will not stop this war. That is because it has become an existential struggle for Vladimir Putin. If he loses he knows his days in power are surely numbered. The possibility of being overthrown or facing an international criminal tribunal will be on his mind.

His goal is to remove the government in Kyiv and install a puppet regime. Anything short of that leaves him vulnerable to an unending resistance in Ukraine. To those who know the country and how it has changed over the past eight years, his goal of suppression seems very unrealistic, even if he gains a short-term military victory.

Still, at this stage, he has every reason to continue prosecuting his war, however great the cost in lives.

The Ukrainians have shown themselves to be more than savvy in the information war. They are quick to adapt and are innovative in the military confrontations. They fight as people who fear to lose their homeland to a foreign invader. But facing a military force with immense superiority in numbers, their best hope is to pull the Russians into a draining war of attrition.

As more cities are shelled and Russia piles suffering on civilians, as details of war crimes emerge, how do the allies respond when sanctions cannot make the artillery fall silent? Having ruled out a military involvement, for fear of a horrendous wider European war, the West will have to consider how it responds to the sight of besieged cities under Russian bombardment.

There are no easy answers. We are truly in an unknown landscape.

We have some more from Sergei Lavrov.

He repeats the Russian claim that the Ukrainian government is a neo-Nazi regime and says gangs are looting towns and cities, including in Mariupol. The BBC has seen no evidence to support these claims.

Lavrov also says the Ukrainians are "now trying to use civilians as human shields".

He repeatedly refers to Hollywood and says that people should not "just look at this Hollywood movie" written by the Western media "where there is an ultimate evil".

The Russian foreign minister also says that Nato is trying to bolster the West's security at the cost of Russia's.

He compares the US to Napoleon and Hitler, saying "back in the days, Napoleon and Hitler had a goal to subjugate Europe - now Americans do so".

He says the cancelling of the Nordstream 2 gas pipeline "shows the place" of the EU, suggesting the US was behind the decision.

As we have been reporting, more than one million people have fled Ukraine since the invasion, according to the UN.

The EU estimates that up to four million people may try to leave the country in total.

Poland has so far taken in more than 575,000 people since the conflict began, the Polish Border Guard agency says.

The agency said 95,000 people had entered Poland from Ukraine on Wednesday alone, slightly down from Monday’s record high of 100,000.

By 06:00 GMT today, another 27,100 people had crossed the border, it added.

Poland is home to a large Ukrainian community that is estimated to be between one and two million, and many people fleeing the war have gone to stay with family or friends.

Those with nowhere to stay are being transported to makeshift accommodation centres in fire stations and sports halls across the country.

Many Poles are also offering to house refugees in their own homes.

Image source, Volodymyr Zelensky

Meanwhile, as Sergei Lavrov speaks in Moscow, Ukraine's President Volodymyr Zelensky has released a new video.

He claims Ukraine's defence lines are holding up, but says there has been no let up in Russia's shelling of cities since midnight.

He says the change in Russia's tactic - to targeting of civilian areas - shows that Ukraine has been successful in resisting Moscow's plan for a quick victory via land assault.

"We have nothing to lose but our own freedom," Zelensky says, adding that Ukraine is getting daily arms supplies from its international allies.

His comments come after an investigation into possible war crimes was launched, with Russia accused of bombing civilians.

Russian Foreign Minister Sergei Lavrov is giving a news conference in Moscow.

He says that US President Joe Biden has said the only alternative to sanctions is a third world war - and Lavrov goes on to say that a third world war could only be "nuclear war".

He says that is only in the heads of Western politicians - and is not in the heads of the Russian people.

"If real war is waged against us then those who make such plans should think about it [and] in my opinion such plans are being made," he says.

We'll bring you more lines from Lavrov's conference soon.

Some more footage now of the explosions that rocked Kyiv overnight - this time caught by a CBS News crew finishing off a segment.

Charlie d'Agata was visibly caught off guard by the blasts, which he likened to lightning.

The correspondent is in Kyiv for the BBC's US partner CBS.

Will Vernon
BBC News, Moscow

The list of international companies and organisations that are curtailing or ceasing operations in Russia continues.

The latest: the World Bank, Spotify, and H&M.

H&M announced today it was ceasing all sales in Russia. The chain is hugely popular in the country, with over 155 stores, placing Russia in the top ten countries in the world by number of outlets.

The World Bank has announced it is halting all programmes in Russia and Belarus with immediate effect.

The bank had already scaled down its operations significantly since Russia’s annexation of Crimea in 2014, not approving any new lending since then.

Another Kherson resident tells Today he has opened a volunteer centre to help people with food, water and medicine as the city falls under Russian control.

Speaking on the BBC Today programme, he says food supplies are insufficient and there are many wounded civilians who need to be taken out of the city for treatment.

He says the Russians are "not allowing the Red Cross to bring medicine and ambulances to help people".

"I have already had this experience in Donetsk in 2014 and I came here to Kherson," he adds.

"I think in a couple of years we will have a completely different Ukraine and it will be a completely free Ukraine, not under Russia."

Image source, Reuters

We've been reporting that Russian forces have seized control of the key southern port city of Kherson – the first major Ukrainian city to be taken since the start of the invasion.

One resident sheltering at home in the city with his family says the locals are "not afraid" of the Russian soldiers.

He tells the BBC's Today programme: "Since the start of the war I went outside only once – just for 10 minutes – to the supermarket downstairs to get some food.

"I just look out of the window and see the Russian soldiers and Russian tanks, and I read all the local news, I just don’t go outside because it’s really dangerous now."

He says other locals had been approaching the soldiers on the street and telling them to leave.

"People are not afraid of the soldiers – in our souls we are not afraid of Russia.

"The soldiers are saying: 'Guys, we don't like the situation too – we will not touch you and maybe in a couple of days we will leave, we are waiting for an order'.

"From their behaviour it’s clear they're unhappy to be here."

He says the Ukrainian flag remains above the city's government building.

"It's a strange situation when the city is occupied but nothing apart from the Russian army [presence] shows it’s under control."

Image source, Getty Images

Russia's education ministry has announced that schoolchildren throughout the nation will be given a virtual lesson on "why the liberation mission in Ukraine is a necessity".

The broadcasted instruction will take place at 12:00 Moscow time (09:00GMT) on Thursday.

Viewers will be taught "about the danger Nato represents to our country" and "why Russia stood up for the protection of the civilians of the Donetsk and Luhansk People's Republics".

A statement on the ministry's Facebook page said children will also learn "how to distinguish the truth from lies in the huge stream of information, photos and videos that are flooding the internet today".

The French government is telling its citizens to leave Russia in light of the escalating conflict if their presence there is not "essential".

Other countries have similar travel advisories in place.

The UK Foreign Office, external "advises against all travel to the whole of Russia" due to difficulties in leaving the country and what it describes as the "increased volatility" of the Russian economy.

The US State Department, external is advising the same. It cites multiple factors including "the potential for harassment against US citizens by Russian government security officials".

Lyse Doucet
Chief International Correspondent, in Kyiv

It’s day eight of Russia’s invasion of Ukraine.

Just past midnight in Kyiv, the air raid siren blared yet again. The quiet in the dead of night was shattered by several large explosions.

This is the soundtrack of this city now. In a capital where many can’t sleep, images were posted on social media of a huge orange fireball lighting the sky.

The day dawned very cold, grey. It’s another morning where residents of Kyiv hear that Moscow's mammoth armoured convoy on the edge of city is still stalled.

"The column has made little discernible progress in over three days," Ukraine’s defence ministry said in a statement.

Reports speak of possible shortages of food and fuel, of wheels stuck in the mud, of restive Russian forces, and Ukrainian resistance.

On the rim of a beleaguered city, there are reports of heavy fighting and roads are strewn with burnt and blackened carcasses of military vehicles.

Across Ukraine, mayors send updates of their cities' desperate plight.

Mayor Igor Kolykhaiev, who once presided over the southern port city of Kherson, posted a message on Facebook informing residents that the Ukrainian flag still flies over their city, but there were no Ukrainian forces.

He told invading troops, who now control the first major city, "not to shoot people".

Mayor Vadym Boychenko of Mariupol, now under intense shelling and a deepening humanitarian catastrophe, reported that Russian attacks were being repelled "with dignity".

More than a million Ukrainians have fled; many more keep fighting as Russia advances and attacks with devastating force in the north, east, and south of the country.

Image source, Thomas Lovelock for OIS/PA

Some more details now on the breaking news that athletes from Russia and Belarus have both been banned from competing in the 2022 Winter Paralympics in Beijing, due to start tomorrow.

A statement on Thursday, external from the International Paralympic Committee (IPC) said the "situation in the athlete villages is escalating and ensuring the safety of athletes has become untenable".

The initial IPC decision to allow 71 Russians and 12 Belarusians to compete as neutrals drew heavy criticism.

"We are very firm believers that sport and politics should not mix," IPC president Andrew Parsons said in a statement today.

"However, by no fault of its own the war has now come to these Games and behind the scenes many governments are having an influence on our cherished event."

Will Vernon
BBC News, Moscow

The port city of Mariupol on the Black Sea coast continues to come under sustained attack.

The mayor of the city has made a desperate video address, saying: "We cannot even take the wounded from the streets, from apartments, since the shelling does not stop."

The Russian Defence Ministry has urged civilians to leave the city via a so-called ‘green corridor.’

Today, a pro-Russian rebel spokesman said they would launch "targeted strikes" against the city unless Ukrainian forces there surrender.

Image source, 2022 MAXAR TECHNOLOGIES

Little progress has been made in the last three days by the long convoy of Russian forces approaching Kyiv, according to a British military intelligence assessment.

The main body of the military column, which is approaching the capital from its north, "remains over 30km from the centre of the city having been delayed by staunch Ukrainian resistance, mechanical breakdown and congestion".

The defence ministry update also adds , externalthat the cities of Kharkiv, Chernihiv and Mariupol remain under Ukrainian control.

On Russia's casualty figures, the UK predicts that the actual numbers are "considerably higher" than the 498 killed and 1,597 wounded declared so far by Moscow.

An adviser to the Ukrainian president says "humanitarian corridors" should be set up into occupied parts of the country to allow humanitarian aid from international organisations to reach them.

Mykhailo Podolyak also accuses Russian forces of allowing the Ukrainian areas under their control to become "places of looting, robbery, murder".

Athletes from Russia and Belarus will not be allowed to compete at the 2022 Winter Paralympics in Beijing, the International Paralympic Committee has said.

We will bring you more on this as it unfolds.

Image source, EPA

If you're just joining us, here's an update of what we know on day eight of Russia's invasion of Ukraine

In Kyiv:

• Four major explosions in the past few hours have been captured on video by witnesses, but it’s unclear what the targets were of if there were casualties
• BBC correspondents say the blasts could be heard from two storeys underground in their bunker

• A US defence official says a massive convoy of Russian military vehicles close to Kyiv has "stalled" due to fuel and food shortages

In the south:

• Russian forces have seized control of the key port city of Kherson, according to local officials. It's the first major Ukrainian city to be taken since the invasion began

• In the port city of Mariupol, hundreds of people are feared dead following hours of sustained shelling, the city's deputy mayor says. Ukraine's military claims the city remains in Ukrainian hands

In the northeast:

• There has also been heavy shelling of the country's second city, Kharkhiv

In other developments:

• Ukrainian President Volodymyr Zelensky released a late-night video, praising the courage of citizens in defending their country
• More than one million people have now fled Ukraine since the start of the invasion, the UN says, with the number rising rapidly
• An investigation into possible war crimes in Ukraine has been launched by the International Criminal Court in The Hague
• Russia has for the first time said it sustained heavy military casualties during its attack on Ukraine, with 498 troops killed and a further 1,597 injured. Ukraine has claimed that far more Russian troops have been killed. The BBC cannot independently verify these claims.