Ukraine accused Russia on Thursday of attacking a theater in Mariupol that was sheltering over 1,000 civilians, after US President Joe Biden’s labeling of Vladimir Putin as a “war criminal.”

The latest assaults on civilians in Ukraine occurred as President Volodymyr Zelensky made an impassioned plea for assistance to the United States, which reacted by providing $1 billion in fresh armaments to combat Russia’s invading troops.

Officials in Ukraine are straining to tally the civilian deaths, with officials reporting 103 minors murdered since the invasion began, who were targeted in homes, hospitals, ambulances, and food lines.

In the coastal city of Mariupol, where over 2,000 people have perished so far, a Russian bomb exploded near the Drama Theatre, which municipal council authorities say housed over 1,000 people. “The only word to describe what has happened today is genocide—the genocide of our nation, our Ukrainian people,” said Vadim Boychenko, the city’s mayor, in a video message on Telegram.

On March 14, commercial satellite company Maxar revealed satellite photographs of the theater that clearly showed the words “children” inscribed in the earth on either side of the structure.

After claiming that a bomb was thrown from an airplane, officials shared a photo of the building’s center section, which was entirely demolished, with dense white smoke billowing from the wreckage.

So far, the damage that has ravaged neighboring towns has been halted outside of Kyiv, the capital, which has been evacuated of about half of its 3.5 million inhabitants.

However, dull booms sounded over the capital’s desolate streets on Wednesday, with just the rare car passing through sandbagged checkpoints and very few permissions allowed to violate the city’s newest curfew.