Iran held a mass funeral for 165 female students and staff in what was described as a U.S. and Israeli attack on a girls’ school in the southern city of Minab.

Saturday’s attack came on the first day of a joint U.S.-Israeli attack on Iran. It was the deadliest incident so far in the operation against Tehran.

The Israeli military said it was not aware of any attacks by Israel or the United States in the area. However, during its genocidal war in Gaza, Israel has repeatedly denied responsibility for deadly attacks on Palestinian civilians, only to later recant after evidence emerged, often describing such incidents as “accidents.”

The Minab attack was condemned by UNESCO and Nobel Peace Prize-winning education activist Malala Yousafzai.

Deliberate attacks on educational institutions, hospitals or any other civilian buildings constitute war crimes under international humanitarian law.

Iranian Foreign Ministry spokesman Esmail Baghaei said on Monday that the two countries “continue to attack residential areas indiscriminately, sparing neither hospitals, schools, Red Crescent facilities nor cultural monuments.”