Theatre sheltering more than 1,000 civilians bombed in Ukraine

[KYIV] Ukraine accused Russia on Thursday of bombing a theatre that was sheltering more than 1,000 civilians in the city of Mariupol, after US President Joe Biden branded Vladimir Putin a "war criminal".

The latest assaults on civilians across Ukraine came as President Volodymyr Zelensky made a searing appeal for help to the US, which responded by pledging US$1 billion in new weapons to fight Russia's invading army.

Officials across Ukraine are struggling to count the civilian dead - with authorities saying 103 children have been killed since the invasion began - who have been targeted in homes, hospitals, ambulances and food queues.

In the port city of Mariupol - where more than 2,000 people have died so far - a Russian bomb hit the Drama Theatre, which city council officials said had been housing over 1,000 people.

"The only word to describe what has happened today is genocide, genocide of our nation, our Ukrainian people," the city's mayor Vadim Boychenko said in a video message on Telegram.

"We have difficulty understanding all of this, we refuse to believe, we want to close our eyes and forget the nightmare that happened today," he said.

Satellite images of the theatre on March 14 shared by private satellite company Maxar showed the words "children" clearly etched out in the ground in Russian on either side of the building.

Officials posted a photo of the building, whose middle part was completely destroyed, with thick white smoke rising from the rubble after they said a bomb was dropped from an airplane.

"It is impossible to find words to describe the level of cynicism and cruelty, with which Russian invaders are destroying peaceful residents of a Ukrainian city by the sea," an official statement read.

Russia's defence ministry denied it had targeted the theatre, instead claiming that the building had been mined and blown up by members of Ukraine's far-right Azov Battalion.

So far the destruction that has marked other cities has been halted outside the capital Kyiv, which has been emptied of around half of its 3.5 million people.

But dull booms echoed across the capital's deserted streets Wednesday, with only an occasional vehicle passing through sandbagged checkpoints, and very few permits granted to break its latest curfew.

The mayor of Ukraine's southern city of Melitopol was released days after Kyiv said he was abducted by Russian forces.

AFP