Dozens of Palestinians were found dead at a school in the northern Gaza Strip in black body bags tied with plastic cables bearing Hebrew writing, Middle East Eye reports.

Al Jazeera Arabic and local media reported that the bodies of 30 Palestinians were discovered at the grounds of the Khalifa bin Zayed elementary school in Beit Lahia after Israeli forces withdrew from the area.

The bodies were reportedly discovered under a mound of rubble with videos showing several of the body bags tied with white plastic zip ties, normally used for tying cables together.

It was unclear when the Palestinians were killed, but the school had served as a shelter for thousands of displaced Palestinians before it was bombed and besieged by Israeli forces in early December.