Zelensky says Russian bombing of Ukrainian school killed 60 people

• Zelensky said in his nightly address Sunday that these people were civilians "who simply hid in the school from the shelling," according to a transcript posted in English on his presidential website.
• "It was a targeted strike at the school. Another crime of the occupiers," Zelensky added.
• Emergency workers first on the scene discovered rescued 30 people and discovered two bodies among the debris, Gaidai said in a Telegram message.

Meanwhile, UNICEF executive director Catherine Russell issued a statement condemning the bombing.

• "We do not yet know how many children might have been killed or injured in the reported bombing, but we fear this attack has just added to the hundreds of children who have already lost their lives in this war," she said.
• Targeting civilians and civilian objects, including schools, is a violation of international humanitarian law," Russell added.

For the record: The Kremlin has repeatedly denied that its forces have targeted civilians or committed any other war crimes.

Between the lines: War crimes have been historically hard to investigate, and often they're even more challenging to prosecute, per Axios' Laurin-Whitney Gottbrath.

The big picture: Russia launched a major offensive in the Donbas last month that both sides have characterized as a decisive "second phase" of the war, Axios' Zachary Basu writes.

• After several weeks, the U.S. believes Russian forces are "behind schedule" and experiencing many of the same problems that forced them to retreat from Kyiv.
• The Kremlin did not immediately comment on Ukrainian officials' reports of the school bombing.

Editor's note: This article has been updated with comment from Zelensky and Russell, and with further context.

Go deeper: What counts as a war crime and why they're so hard to prosecute