More than 80 Palestinians were killed across Gaza on Thursday, according to health officials, as Israel intensified its strikes across the strip.

The deaths, which authorities said included dozens of people seeking aid, come as negotiations to reach a ceasefire in the enclave ramp up. A source told CNN that Hamas officials were set to meet Thursday to prepare a response to the latest proposal, which has been accepted by Israel.

At a school-turned-displacement facility in Gaza City, 15 people were killed and 25 injured in Israeli strikes that left many with severe burns, the director of Al-Shifa hospital Dr. Mohammad Abu Silmiya said. The hospital is treating those wounded in the attack.

“The scene was extremely harrowing due to the charred bodies of the martyrs and children,” said Fares Afana, who heads the Emergency and Medical Services in northern Gaza, and had teams evacuating the injured from the school.

The hospital director said another 12 people were killed in other strikes in Gaza City.