Pictures show the destruction caused after Russian forces dropped a powerful bomb on a theatre in the encircled Ukrainian port city of Mariupol.
Hundreds of civilians were sheltering in the Donetsk Regional Theatre of Drama which was destroyed by an airstrike on Wednesday, Ukraine's foreign ministry said.
The ministry said many people were trapped in the theatre and accused Russia of committing a war crime. It said the number of casualties was not yet known.
Russia denies targeting civilians. In Moscow, the defence ministry said its forces had not struck the building and instead accused the Azov Battalion, a far-right Ukrainian militia, of blowing it up, RIA news agency said.
It did not give evidence to back up the claim. Russia had previously accused the battalion of preventing civilians from leaving the city, which has come under heavy bombardment.
Video footage, from Maxar Technologies, shows satellite images of Mariupol theatre before the bombing.
Maxar Technologies, a private US company, distributed satellite imagery that it said was collected on March 14 and showed the word "children" in large Russian script painted on the ground outside the red-roofed Mariupol Drama Theatre.
Maxar MAXR.N said it would distribute new images of the theatre as soon as it has them.
Pictures showing the impact of Russian airstrikes on Mariupol here:
A view shows Donetsk Regional Theatre of Drama destroyed by an airstrike amid Russia's invasion of Ukraine, in Mariupol.
DONETSK REGIONAL ADMINISTRATION
A satellite image shows a closer view of Mariupol Drama Theatre before bombing, as a word "children" in Russian is written in large white letters on the pavement in front of and behind the building.
MAXAR TECHNOLOGIES
An armoured vehicle with a "Z" marking is attacked, amid Russia's ongoing invasion of Ukraine, in Mariupol.
AZOV HANDOUT
An aerial view shows smoke rising from damaged residential buildings following an explosion.
AZOV REGIMENT PRESS SERVICE
A satellite image shows a color infrared view of fires burning near Fontanna street, in eastern Mariupol.
MAXAR TECHNOLOGIES
People fleeing from Mariupol amid Russia's invasion of Ukraine stand next to a police officer, in the Zaporizhzhia region.
NATIONAL POLICE OF UKRAINE
A view shows Donetsk Regional Theatre of Drama destroyed by an airstrike.
DONETSK REGIONAL ADMINISTRATION
A convoy of cars with people fleeing from Mariupol amid Russia's invasion of Ukraine is seen in the Zaporizhzhia region.
NATIONAL POLICE OF UKRAINE