Israel has ordered the closure and evacuation of one of the last hospitals still partly functioning in a besieged area on the northern edge of the Gaza Strip, forcing medics to search for a way to bring hundreds of patients and staff to safety.

The head of the Kamal Adwan hospital in Beit Lahiya, Husam Abu Safiya, told Reuters via text message that obeying the order to shut down was “next to impossible” because there were not enough ambulances to get patients out.

“We currently have nearly 400 civilians inside the hospital, including babies in the neonatal unit, whose lives depend on oxygen and incubators. We cannot evacuate these patients safely without assistance, equipment, and time,” said Abu Safiya.

“We are sending this message under heavy bombardment and direct targeting of the fuel tanks, which if hit will cause a large explosion and mass casualties of the civilians inside,” he said.

The Israeli military did not respond to a request for comment on Abu Safiya’s remarks. It claimed that on Friday it had sent fuel and food to the hospital and helped evacuate more than 100 patients and caregivers to other Gaza hospitals, some in coordination with the Red Cross, for their own safety.

Abu Safiya said the military had ordered patients and staff to be evacuated to another hospital where conditions are even worse. Photos from inside the hospital showed patients on beds crammed into corridors to keep them away from windows. Reuters could not immediately verify those images.