Ukrainian officials have accused Russia of purposely destroying a theatre in Mariupol on Wednesday where about 1,200 people were sheltering.

"The bomb strike demolished the central part of the theatre building, casuing large numbers of people to be buried under the debris," Ukraine's Foreign Ministry said in a statement.

Assessing casualty levels was currently impossible "due to the ongoing shelling".

The foreign minister has tweeted a before and after of the theatre.

The BBC has not been able to verify the second image of the destruction.

If you're just joining our live coverage, or want a recap, here are the latest headlines:

• With the war in Ukraine entering its third week, the war of words between world leaders has escalated significantly
• US President Joe Biden called Russian President Vladimir Putin a "war criminal"in brief remarks to reporters at a domestic event on Wednesday
• Russia swiftly condemned the comments, denouncing Biden's "unacceptable and unforgivable rhetoric" and accusing the US of killing "hundreds of thousands of people around the world"
• Ukrainian President Volodomyr Zelensky spoke to the US Congress in a virtual address in which he invoked Pearl Harbor and 9/11 and called for more Western support
• In an address to the Ukrainian people later in the day, he claimed that Russian losses have been higher than the wars in Syria, Afghanistan and Chechnya
• The US pledged an additional $1bn (£764m) in weapons to Ukraine - including tactical drones, rocket and grenade launchers, rifles, machine guns, body armour, and ammunition
• A theatre sheltering some 1,200 civilians in the southern Ukrainian city of Mariupol was reportedly hit with a large Russian bomb
• In the northern city of Chernihiv, 13 people waiting in a queue for bread were reportedly killed by Russian shelling
• The mayor of Melitopol, one of the first cities to fall to Russia, has been released in exchange for nine Russian conscripts, according to Ukraine

• More than three million people have now fled Ukraine, according to the United Nations

This is Jude Sheerin in Washington DC signing off and handing over to my colleagues Ayeshea Perera and Frances Mao in Singapore.

Wednesday's live coverage was also brought to you by Boer Deng, Nathan Williams, Max Matza, Alys Davies, Leo Sands, Francesca Gillett, Sam Cabral, Joseph Lee, James Clarke, Bernd Debusmann, Alice Evans, Annabelle Liang and Tessa Wong at BBC locations around the world.

Image source, Getty Images

Ukraine will plant crops this spring in all regions where there are no direct hostilities, Ukraine's minister of food Roman Leshchenko says.

He tells the Interfax-Ukraine news agency the country will be able to ensure its own food security this year.

"Where we can physically sow, where there is no shooting and where there is an opportunity to go into the field - we go into the field and plant. And not only in western Ukraine, but also in the central and southern regions. We will sow wherever we can."

But concerns remain for countries that rely on exports from Ukraine for staples such as wheat. The World Food Programme has said Lebanon, Yemen, Syria, Tunisia are particularly dependent on grains grown in Ukraine.

Leshchenko says exports will depend on what Russia does, with actions like blocking seaports or bombing railway infrastructure putting them at risk.

Image source, Facebook/ Zelensky

In his latest nightly address, external, Ukraine's President Volodymyr Zelensky claimed Russia's losses in Ukraine were higher than in the wars in Syria, Chechnya and Afghanistan.

Addressing Russians in Russian, Zelensky said: "Russian troops suffer such losses in Ukraine, which were inflicted neither in Syria, nor in Chechnya. Neither did the Soviet troops suffer such losses in Afghanistan."

It's unlikely the message will have been heard by many in Russia, where information about the war is being tightly controlled.

How Zelensky arrived at this projection is unclear.

US intelligence estimates that more than 7,000 Russian troops have died during the invasion of Ukraine.

According to various estimates, about 15,000 Soviet troops died in the Afghan war (1979-89), at least 13,000 Russian troops died in the Chechen wars, and the Russian death toll in Syria is listed in the hundreds.

Image source, Getty Images

US state department spokesman Ned Price has backed President Joe Biden's labelling of Vladimir Putin on Wednesday as a "war criminal".

"When you are speaking from the heart, speaking as a human and you're seeing what we've all seen, these searing images on TV, a Russian strike on a maternity hospital in Mariupol, strikes against residential buildings, against schools, against civilian neighbourhoods, it's hard not to walk away with that conclusion,” he told CNN.

His remarks echo those by Biden spokeswoman Jen Psaki as she delivered the daily White House briefing earlier on Wednesday.

Psaki said Biden, while appearing at a domestic event, had been "speaking from his heart" after seeing "barbaric" images of the violence in Ukraine.

Russia has angrily condemned the "unacceptable and unforgivable rhetoric", with officials in Moscow accusing the Americans of having killed "hundreds of thousands of people around the world".

Earlier, we reported that the mayor of Melitopol was released after allegedly being held hostage by Russian troops for more than five days.

Now, new reports are emerging which say Mayor Ivan Fedorov was exchanged for nine Russian prisoners.

Speaking on Ukrainian television, a press secretary to Ukraine's president said the Russian conscripts were between 18 and 19 years old.

Following Fedorov's abduction five days ago, residents of Melitopol came out to protest against his abduction.

Harry Farley
Religion reporter, BBC News

Image source, Getty Images

The Archbishop of Canterbury has urged the head of the Russian Orthodox Church “to join him in speaking for peace in public” in the pair’s first known conversation since the war began.

Patriarch Kirill is the head of the Russian Orthodox Church and a close ally of Russian President Vladimir Putin.

He has defended the Russian invasion and shortly after Russian troops entered Ukraine he called Moscow's opponents in that country "evil forces".

Lambeth Palace said Archbishop Welby had “expressed his grave concern about the war in Ukraine, which he said is a great tragedy”.

“He [the Most Rev Justin Welby] stressed the need for an end to the violence in Ukraine and said that war and violence is never an answer".

The Russian Orthodox Church said "a detailed discussion of the critical situation in Ukraine took place" between the Archbishop of Canterbury and the Patriarch, adding that the pair discussed "the humanitarian aspect" of the crisis.

The Pope has also spoken to Patriarch Kirill regarding the war.

In this video, verified by the BBC, smoke can be seen billowing out of buildings struck by shelling in Mariupol's central market, in south-eastern Ukraine.

Earlier today, a theatre sheltering between 1,000 and 1,200 people was attacked in the city, according to the city's deputy mayor. The number of casualties is unknown.

The city has been continuously shelled since Russia invaded Ukraine, with water and electricity supplies in the city cut off.

Image source, AeroVironment Inc.

The US is sending 100 killer-drones to Ukraine as part of a huge military aid package announced today by the Biden administration, says the Associated Press, quoting a US official "familiar with the decision".

The US military source, who spoke on condition of anonymity, said the weapons system discussed is the Switchblade 300- a backpack-worn weapon known to US forces as a "kamikaze drone".

Congressional officials told NBC News the missile system is designed for "pinpoint strikes on personnel" and can be accurately shot from milesaway directly at its target.

The weapons - though of Russian design - are owned by some European Nato members and are therefore seen as easy to integrate into Ukraine's military, according to AFP.

Gordon Corera
Security correspondent, BBC News

Image source, EPA

The head of security policy at Meta - the parent company of Instagram and Facebook - says the company has spotted and taken down a deep fake video of Ukraine's president.

“Earlier today, our teams identified and removed a deep fake video claiming to show President Zelensky issuing a statement he never did. It appeared on a reportedly compromised website and then started showing across the internet,” tweeted Nathaniel Gleicher.

“We've quickly reviewed and removed this video for violating our policy against misleading manipulated media, and notified our peers at other platforms.”

The deep fake, in which Zelensky tells people to lay down their arms, is poorly made, implausible and easy to spot.

There have been many concerns about the use of deep fakes as a tool to manipulate opinion. Even though this video is unlikely to have significant impact it may be a sign of what's to come.

Learn more about the technology here:

Deepfake technology: Can you spot what's real?

Image source, Mandi Arnold

Two days before Russia invaded Ukraine, Mandi and John Arnold were curled up on the sofa of their home in Shropshire, England, streaming a film about the Chernobyl nuclear disaster on Netflix.

It struck a nerve with the mum-of-four - she and John were both born in 1986, the same year as the disaster. So later that week when Mandi saw news of millions of Ukrainians fleeing their homes to escape Russian attacks, including in the Chernobyl area, she jumped at the chance to help.

"From the moment this all started to evolve, my heart just went straight out to them," she says.

Mandi, 35, is among more than 120,000 people to have registered their interest in a new visa scheme allowing people in the UK to host Ukrainian refugees in their own homes.

Her family has "all the love to give" to make refugees feel welcome, she says.

Image source, Mandi Arnold

Mandi can relate to the feeling of disconnect many Ukrainian refugees might have as they set foot on UK soil for the first time. She fled an abusive relationship when she was younger, leaving her network of friends and family behind to start a new life.

"I know the feeling of removing yourself from somewhere that you once called home.”

Read more here.

Image source, Getty Images

In his nightly video address, Ukrainian President Volodymyr Zelensky says: "The world must officially recognise that Russia has become a terrorist state."

Zelensky reiterated his calls for more sanctions against Russia, more weapons for Ukraine and a no-fly zone.

The Ukrainian leader also said "real protection" for his country was a prerequisite for any negotiations with Russia to succeed.

"My priorities in the negotiations are absolutely clear: the end of the war, security guarantees, sovereignty, restoration of territorial integrity, real guarantees for our country, real protection for our country," he said.

Image source, Getty Images

The US says it has warned Russia of "consequences and implications of any possible Russian decision to use chemical or biological weapons in Ukraine".

Joe Biden's National Security Adviser Jake Sullivan spoke over the phone on Wednesday with the secretary of the Russian Security Council, General Nikolay Patrushev.

The White House said it had requested the call, its highest-level diplomatic engagement with Moscow since a February call between Secretary of State Antony Blinken and his counterpart Sergei Lavrov.

Both countries have accused the other of housing and preparing to use biological weapons inside Ukraine.

General Patrushev is one of three Putin loyalists who have served with him since the 1970s.

Here's more on the general and other members of Putin's inner circle.

Image source, Getty Images

Russian prima ballerina Olga Smirnova has left the Bolshoi Ballet, Russia's internationally renowned company, after saying she is "against war with all the fibres of my soul".

She joins the Dutch National Ballet, which describes her as one of the Bolshoi's leading stars, and that it had become "untenable" for her to continue working in Russia after she condemned the invasion of Ukraine.

Earlier this month, she said on Telegram: "I never thought I would be ashamed of Russia, I have always been proud of talented Russian people, of our cultural and athletic achievements. But now I feel that a line has been drawn that separates the before and the after.

"It hurts that people are dying, that people are losing the roofs over their heads or are forced to abandon their homes."

You can read more about Smirnova's move here.

The UK's Ministry of Defence has released its latest update on Russia's military, saying that it has probably had to resort to using older and less precise weapons, which are more likely to result in civilian casualties.

It adds that Russia probably resorted to using these weapons as a result of failing to achieve its military objectives.

So far the UN has confirmed the deaths of 729 civilians in Ukraine, though the actual number is expected to be far higher.

Image source, Reuters

The mayor of Melitopol, who was reportedly kidnapped by Russian forces five days ago, was freed after Ukraine agreed to exchange nine captured Russian soldiers for him, according to a senior Ukrainian presidential aide.

The capture of Ivan Federov - the leader of one of the first cities captured by Russia - led President Zelensky to accuse Russia of starting a "new stage of terror".

The Russian soldiers exchanged had all been born between 2002-03, making them "actually children", Zelensky press aide Darya Zarivnaya said in a televised address.

Earlier on Wednesday, Ukrainian presidential aides said that Federov had been released after an "operation", but did not provide further details.