Image source, Reuters

Russia has denied any involvement in civilian deaths in the town of Bucha, insisting that photographs showing the bodies were "fakes" concocted by Ukraine. But several probes are debunking some of these claims.

One claim centred on footage taken from a car as it drove through the town showing what appeared to be dead bodies on either side of the road.

Pro-Russian social media accounts then circulated a slowed-down version of the video, claiming that the arm on one of the bodies moved and were not lifeless.

But the BBC's Reality Check and Monitoring teams have since verified multiple images of the same scene separately captured by news agency AFP, clearly showing a dead body in the same position and place as the video.

You can read more about our investigation and other debunked claims here.

Meanwhile, satellite images analysed by the New York Times, external appear to confirm that many civilians were killed more than three weeks ago, when Russian forces were in control of Bucha.

The newspaper says a before-and-after analysis of the imagery shows objects of a similar size to a human body between 9 and 11 March in the precise positions where bodies were found after Ukrainian forces reclaimed the town last week.

To our readers waking up in the UK, welcome. Here's the latest developments:

• World leaders are reacting in horror to the documented reports of civilian killings in Bucha, a town near the capital Kyiv, with the US and European allies warning of intensified sanctions on Russia
• Russia's UN ambassador has denied any massacre in Bucha and accused Ukraine of engaging in a "staged provocation" with Western countries, although Russia has provided no evidence of this
• Ukrainian authorities said the bodies of 410 civilians had been found in the areas around Kyiv so far, although the BBC can't independently verify this figure
• Ukrainian President Volodymyr Zelensky has accused Russia of genocide, and is due to address the UN Security Council on Tuesday. He is expected to report what he witnessed in Bucha earlier this week - his first trip outside the capital since the start of the invasion
• Multiple reports from Western analysts indicate that Russian forces have retreated from the north of the country, including areas near the capital Kyiv, and are aiming to regroup and focus on taking eastern Ukraine

And with that, this is Tessa Wong and Zubaidah Abduljalil signing off in Singapore. Our colleagues Chris Clayton and Jack Burgess in London will continue bringing you the latest developments.

More Russian troops are withdrawing from their advance on Ukraine’s capital city of Kyiv as invading forces intensify their attack, external in the separatist region of Donbas in the east, a senior U.S. defence official told US military news outlet Stars and Stripes.

Speaking on condition of anonymity, he said two-thirds of the Russian battalion tactical groups surrounding Kyiv had appeared to retreat north towards Belarus - a Russian ally.

The official said they believed the retreating Russian troops would be "refit, resupplied, perhaps maybe even reinforced with additional manpower" before being sent back into Ukraine to continue fighting elsewhere.

Signals that Russians were instead refocusing towards the east appeared when several Russian troops located north of the southern city of Mariupol appeared "to push north to Donetsk,” located in the Donbas region.

Russia's pivot away from the capital city comes after weeks of stalled movement toward Kyiv.

Russia’s defence ministry now claims their goal was always to “liberate” the Donbas region, despite evidence that their initial goals were to capture major cities across Ukraine.

In recent hours the US and Western allies have warned they will punish Russia for its actions in Bucha.

German Chancellor Olaf Scholz said on Monday that Russian president Vladimir Putin and his supporters would "feel the consequences" and that Western partners would intensify sanctions against Moscow.

Meanwhile US national security adviser Jake Sullivan said the US was working "intensively with its European allies on further sanctions to raise the pressure and raise the cost on Putin and on Russia".

France and Germany has also said they would expel Russian diplomats from their countries.

In response, Russia said it would retaliate and "slam shut the door on Western embassies", Reuters reported Russian ex-president and deputy head of security council Dmitry Medvedev as saying.

"It will be cheaper for everyone. And then we will end up just looking at each other in no other way than through gunsights," he warned.

Image source, Getty Images

China's foreign minister Wang Yi spoke to his Ukrainian counterpart Dmytro Kuleba on Tuesday, with China again calling for talks to end the conflict in Ukraine.

The call is the first reported conversation between the two foreign ministers since 1 March, when Kuleba asked Beijing to use its ties with Moscow to stop the Russian invasion, according to Ukraine's foreign ministry.

"Wars end eventually. The key is how to reflect on the pain, to maintain lasting security in Europe and establish a balanced, effective and sustainable European security mechanism," Wang said, according to the ministry.

"China stands ready to play a constructive role in this regard in an objective position."

Kuleba tweeted that he was "grateful' to Wang Yi for "solidarity with civilian victims".

The call was made at Ukraine's request, Reuters reported.

A close ally of Moscow, China has refused to condemn Russia's actions in Ukraine or to term it an "invasion".

But Beijing at the same time has expressed "unwavering support" for Ukraine's sovereignty. It has also called for peace and has said it is ready to help end the war through diplomacy.

Read more about what China could do to help stop the war in Ukraine.

Image source, EPA

US President Joe Biden has called for Russian President Vladimir Putin to be tried for war crimes as evidence emerges of atrocities allegedly committed by Russian forces in Ukraine.

There is mounting international anger over the alleged killing of civilians in Bucha, a town near the capital Kyiv.

"This guy is brutal," Mr Biden said of the Russian leader, adding that he believes Mr Putin "is a war criminal".

Without evidence, Russia said images of atrocities had been staged by Ukraine.

Read more here.

Russian troops are preparing an offensive against the eastern city of Slovyansk in an effort to push east and link up with other forces in the Donbas region, according to the latest assessment, external from the Institute for the Study of War think tank.

"Efforts by Russian forces advancing from Izyum to capture Slovyansk will likely prove to be the next pivotal battle of the war in Ukraine," the report says.

The Russians must take "Slovyansk as their minimum step".

If they are unable to do so, their effort to capture the eastern Donetsk and Luhansk regions "will likely fail". Russian forces continue to make little to no progress in assaults in those areas, says the think tank.

Ukraine's troops also continue to hold Mariupol and are likely to inflict heavy casualties on the Russians.

"Russian efforts to generate replacements from reservists and feed damaged units from north-eastern Ukraine into frontal assaults in eastern Ukraine are unlikely to increase their chances of success," the report adds.

Russian troops have departed the Chernihiv and Sumy regions in the north, and "will likely completely vacate these regions in the coming days".

Image source, Institute for the Study of War

When humanitarian corridors are opened in Ukraine to get people out of danger zones, rescue teams know they must act to save the most vulnerable.

A BBC crew followed one ambulance team as medics evacuated 12 children, many of them disabled orphans, from the north-eastern city of Sumy.

Image source, Getty Images

Two children born in Ukraine in recent days have been named after British surface-to-air missiles, according to Ukrainian media reports.

The children were a boy named Yan Javelin and a girl named Javelina.

The unusual names were registered in Vinnytsia Oblast, according to former Ukrainian first lady Kateryna Yushchenko, who said it was a sign of gratitude for the Western arms that have been sent to Ukraine.

Read more here about Ukraine's relationship with the Javelin missile:

How 'Saint Javelin' raised over $1m for Ukraine

Image source, Getty Images

Ukraine's President Volodymyr Zelensky has promised to zealously pursue allegations of war crimes against Russian forces in occupied regions of the country.

Speaking during his nightly address to the Ukrainian people, Zelensky said investigators would do their utmost to identify the perpetrators of alleged atrocities.

"We are already doing everything possible to identify all the Russian military involved in these crimes as soon as possible," he said.

"This will be a joint work of our state with the European Union and international institutions, in particular with the International Criminal Court."

"All crimes of the occupiers are documented. The necessary procedural basis is provided for bringing the guilty Russian military to justice for every crime they commit."

The Ukrainian leader added that he had discussed the status of the investigations with EU Commission President Ursula Von Der Leyen, Polish President Andrzej Duda and Austrian Chancellor Karl Nehammer.

Image source, Getty Images

Ukraine's President Volodymyr Zelensky has accused Russia of attempting to cover up evidence of war crimes committed by its troops in occupied areas.

Zelensky, who will address an emergency meeting of the United Nations Security Council on Tuesday, accused Vladimir Putin's regime of mounting a "propaganda" operation to cast doubt over reports that Ukrainian civilians have been murdered by his forces.

"We must also be aware that after the revealed mass killings of civilians in the Kyiv region, the occupiers may have a different attitude to their crimes in another part of our country where they came," the Ukrainian leader said.

"They are already launching a false campaign to conceal their guilt in the mass killings of civilians in Mariupol. They will do dozens of stage interviews, re-edited recordings, and will kill people specifically to make it look like they were killed by someone else."

"They used the same tactics when the occupiers shot down a Malaysian Boeing over Donbas. They blamed Ukraine. They even came up with various conspiracy theories. They even went so far as to claim that the corpses were "thrown" on board the plane before it crashed," he added.

He called on Western leaders to impose further sanctions on Vladimir Putin's regime, saying that the punishments "must finally be powerful".

If you're just joining us, here's the latest as more evidence emerges of atrocities on the ground in Ukraine.

• World officials are reacting in horror to the documented reports of civilian killings in areas around Kyiv

• The BBC's Yogita Limaye visited the basement of a home in Bucha and saw the bodies of five men with their hands bound behind their backs. They appeared to have been shot
• She also saw a shallow grave in the village of Motyzhyn - west of Kyiv - that contained the bodies of four people allegedly shot dead by Russian forces

• Ukrainian authorities said the bodies of 410 civilians had been found in the areas around Kyiv so far, although the BBC can't independently verify this figure
• Ukrainian President Volodymyr Zelensky visited the town of Bucha on Monday, speaking with residents and accusing Russia of genocide
• He claimed that 300 civilians there had been "killed and tortured" and vowed to bring to justice any Russian soldiers who participated in the atrocities
• Zelensky will address the UN Security Council on Tuesday, and is expected to report what he witnessed in Bucha - his first trip outside the capital since the start of the invasion
• A yacht belonging to a Russian oligarch and Putin ally was seized in Spain - the first yacht to be captured as part of a US operation to target Russians in violation of US sanctions

International condemnation

• US President Joe Biden called for Vladimir Putin to face trial over war crimes in Ukraine

• UK Foreign Secretary Liz Truss pledged a "tough new wave of sanctions" on Russia
• European Commission President Ursula von der Leyen said the EU was ready to send investigators to document atrocities

• Germany expelled 40 Russian envoys but rejected an embargo on energy imports from the country
• Speaking in New York, Russia's UN ambassador denied any massacre in Bucha and accused Ukraine of engaging in a "staged provocation" with Western countries

Image source, Getty Images

More from Ukraine's President Volodymyr Zelensky, who has been addressing the Ukrainian people from his office in Kyiv.

Zelensky accused Russian forces of killing and torturing more than 300 civilians in the formerly occupied city of Bucha, where evidence of alleged Russian war crimes have been discovered.

The BBC cannot independently verify this claim.

"We have just begun an investigation into all that the occupiers have done," Zelensky said.

"At present, there is information about more than three hundred people killed and tortured in Bucha alone. It is likely that the list of victims will be much larger when the whole city is checked. And this is only one city."

"There is already information that the number of victims of the occupiers may be even higher in Borodyanka and some other liberated cities," he went on.

"In many villages of the liberated districts of the Kyiv, Chernihiv and Sumy regions, the occupiers did things that the locals had not seen even during the Nazi occupation 80 years ago. The occupiers will definitely bear responsibility for this."

Image source, President of Ukraine

Ukraine's President Volodymyr Zelensky has said he will address an emergency meeting of the United Nations Security Council on Tuesday.

Speaking during his nightly address to the Ukrainian people, Zelensky said it is in Kyiv's interest to have an open and transparent investigation into the alleged killing of civilians in Bucha.

"I would like to emphasise that we are interested in the most complete, transparent investigation, the results of which will be known and explained to the entire international community," Zelensky said.