Sixty civilians died in Russia’s bombing of a school in Ukraine’s Lugansk region this weekend, President Volodymyr Zelenskyy said on Sunday.

“Just yesterday in the village of Bilohorivka, Lugansk region, a Russian bomb killed 60 people. Civilians. They were sheltering from shelling in a regular school which was hit by a Russian air strike,” Zelenskyy said.

Earlier in the day, the governor of the Luhansk region said that about 90 people were sheltering at the school, and as many as 60 of them were feared dead under the rubble.

Spokesman for UN chief Antonio Guterres said the Secretary General was “appalled” by the bombing of the school and called on Russia to spare civilian lives.

“The Secretary-General is appalled by the reported attack on 7 May which hit a school in Bilohorivka, Ukraine, where many people were apparently seeking shelter from the ongoing fighting,” Spokesman Stephane Dujarric said in a statement.

“The Secretary-General reiterates that civilians and civilian infrastructure must always be spared in times of war. This war must end, and peace must be established in line with the Charter of the United Nations and international law,” the statement added.

Despite international condemnation, Moscow maintains that its “strategic military operation” – the label it gave for its war on Ukraine – does not target civilians.