Ukrainian officials say Russian forces have captured a hospital and taken patients and staff hostage in the besieged city of Mariupol, while an estimated 20,000 civilians have fled the encircled city by way of a humanitarian corridor.
The Donetsk regional governor said Russian forces were holding more than 400 people, including patients and doctors, hostage in the basement of an intensive care hospital in Mariupol.
Pavlo Kyrylenko said the hospital was bombed but staff continued to treat patients in the basement as high-rise buildings burned around them.
It comes after a deadly attack on a maternity and children's hospital in the city last week.
Satellite images provided by Maxar show the children's hospital and medical buildings on March 9 before an attack, and then after an attack on March 12.
Kyrylo Tymoshenko, a senior aide to Ukrainian President Volodymyr Zelenskyy, said about 20,000 people had managed to leave Mariupol in 4,000 private vehicles via a designated safe corridor.
Earlier, the Mariupol city council reported 2,000 civilian cars had managed to leave along the humanitarian corridor that runs more than 260 kilometres west to the city of Zaporizhzhia, while another 2,000 cars were waiting to leave along the route.
These before and after satellite images show residential areas of Mariupol before and after Russia's invasion of Ukraine.
EU leaders arrive in Kyiv to meet Zelenskyy
The prime ministers of the Czech Republic, Poland and Slovenia arrived in Kyiv on Tuesday in a show of high-level backing for Mr Zelenskyy, who briefed them on the war with Russia.
The three, who came by train, were the first foreign leaders to visit the capital since Russia invaded last month.
Brief footage released by Mr Zelenskyy's office showed him speaking in Ukrainian and English to Polish Prime Minister Mateusz Morawiecki, Czech counterpart Petr Fiala and Slovenia's Janez Jansa, who were also due to meet Ukrainian officials.
Also in attendance was Polish Deputy Prime Minister Jaroslaw Kaczynski, the leader of the country's ruling PiS party, who is seen as the main decision-maker in the country.
"The aim of the visit is to express the European Union's unequivocal support for Ukraine and its freedom and independence," Czech Prime Minister Petr Fiala said.
The Czech Republic and Poland, former communist members of both the EU and NATO, have been among the strongest backers of Ukraine in Europe since the Russian invasion.
Russia continues bombardment of Ukraine's capital
With the number of people driven from the country by the war eclipsing 3 million, large explosions thundered across Kyiv before dawn on Tuesday (local time) from what Ukrainian authorities said were artillery strikes, as Russia's assault on the capital appeared to become more systematic and edged closer to the city centre.
Mr Zelenskyy said barrages hit four multi-storey buildings in the city and killed dozens of people.
The shelling ignited a huge fire in a 15-storey apartment building and spurred a frantic rescue effort.
The strikes, carried out on the 20th day of Russia's invasion, targeted a western district of Kyiv, disrupting a relative calm that returned after an initial advance by Moscow's forces was stopped in the early days of the war.
The UN said close to 700 civilians had been confirmed killed in Ukraine since the invasion began, with the true figure probably much higher.
The Ukrainian government said new aid and evacuation efforts would take place on Tuesday along nine corridors around the country, including the Kyiv region.
Many past attempts failed amid continued fighting.
Meanwhile, US officials said Russian forces were about 15 kilometres from the centre of the city as of Monday.
Mayor Vitali Klitschko announced a 35-hour curfew extending through to Thursday morning.
Tuesday's artillery strikes hit the Svyatoshynskyi district of western Kyiv, adjacent to the suburb of Irpin, which had seen some of the worst fighting of the war.
Flames shot out of the 15-storey apartment building and smoke choked the air as firefighters climbed ladders to rescue people.
The assault blackened several floors of the building, ripped a hole in the ground outside and blew out windows in neighbouring apartment blocks.
Rescue workers said at least one person was killed.
"Yesterday we extinguished one fire, today another. It is very difficult," a firefighter who gave only his first name, Andriy, said outside the building, tears falling from his eyes.
"People are dying, and the worst thing is that children are dying. They haven't lived their lives and they have already seen this."
Local man Volodymr Trophimov said he watched as a building was hit.
"And then there was a howl, and I watched out of the window, and it crashed into the building and all the windows were smashed," he said.
Shockwaves from an explosion also damaged the entry to a downtown subway station that has been used as a bomb shelter.
City authorities tweeted an image of the blown-out facade and said trains would no longer stop at the station.
A 10-storey apartment building in the Podilsky district of Kyiv, north of the government quarter, was damaged.
Russian forces also stepped up strikes overnight on Irpin and the north-west Kyiv suburbs of Hostomel and Bucha, said the head of the capital region, Oleksiy Kuleba.
"Many streets have been turned into a mush of steel and concrete. People have been hiding for weeks in basements, and are afraid to go out even for evacuations," Mr Kuleba said on Ukrainian television.
Two journalists have also been reportedly killed in the attacks.
Fox News video journalist Pierre Zakrzewski was killed when the vehicle he was travelling in was hit by fire on Monday on the outskirts of Kyiv, the network said.
Another woman, Oleksandra Kuvshinova, was also reported to have been killed, according to Fox News reporter Yonat Friling.
Friling said on social media that Kuvshinova, 24, was killed during attacks on Kyiv on Monday.
'It's a nightmare what Russia is doing'
In the country's east, Russian forces launched more than 60 strikes overnight on Monday night on Ukraine's second-largest city, Kharkiv, according to regional administration chief Oleh Sinehubov.
The strikes hit the city's historical centre, including the main marketplace.
Mr Sinehubov said fires were raging and rescuers pulled dozens of bodies of civilian from the ruins of destroyed apartment buildings.
In Mykolaiv, a strategic southern city near the Black Sea where air strikes killed nine people on Sunday, residents braced for more attacks.
Volunteers prepared food and sorted donated clothes at an abandoned naval yard that was turned into a support centre for soldiers.
Molotov cocktails were on hand to take on invaders.
"We are bombed during the day and during the night," said Svetlana Gryshchenko, whose soldier son was killed in the fighting.
"It's a nightmare what Russia is doing on the territory of Ukraine."
Ukraine's parliament voted to extend martial law for another month, until April 24.
Under the measure, requested by Mr Zelenskyy, men between 18 and 60 are barred from leaving the country so they can be called up to fight.
Peace talks 'sound more realistic'
As for the latest round of talks, Ukrainian presidential aide Mykhailo Podolyak said they were discussing a ceasefire and Russian troops' withdrawal from Ukraine.
Russian Foreign Minister Sergey Lavrov said Moscow would press its demands that Ukraine drop its bid to join NATO, adopt a neutral status and "demilitarise".
Mr Zelenskyy later said peace talks with Russia were beginning to "sound more realistic, but time is still needed" to reach a breakthrough.
He said in a Facebook video address that victory over Russia would require the work of all Ukrainians, including the team negotiating with Russian officials in virtual talks.
Russia wants Ukraine to formally recognise the breakaway provinces of Donetsk, Luhansk and Crimea, in addition to renouncing its ambitions to be part of NATO.
The talks are due to continue on Wednesday.
Earlier, Mr Zelenskyy told northern European leaders that Ukrainians needed to accept the country would not be joining NATO.
"We have heard for many years about the open doors, but we also heard that we can't enter those [NATO] doors," he told leaders of the Joint Expeditionary Force (JFE) via video-link.
NATO does not admit nations with unsettled territorial conflicts.
Mr Zelenskyy also said JFE could "help yourself by helping us," as he appealed for more weapons to counter Russia's invasion, adding that Ukraine was pushing for a full trade embargo with Russia.
"We have to acknowledge Russia as a rogue state and there has to be a trade embargo with Russia," Mr Zelenskyy said.
White House shrugs off Russian sanctions
The White House made light of Russia's retaliatory sanctions against US officials on Tuesday, saying Moscow may have inadvertently sanctioned Joe Biden's dead father by omitting the suffix "junior" from the US President's name.
Earlier, Russia said it had placed Mr Biden, Defence Secretary Lloyd Austin, CIA chief William Burns, National Security Adviser Jake Sullivan, White House press secretary Jen Psaki and a handful of other US officials on a "stop list" that bars them from entering the country.
"I would first note that President Biden is a junior, so they may have sanctioned his dad," Ms Psaki told reporters.
"None of us have bank accounts that we won't be able to access. So we will forge ahead."
ABC/AP
