WHO said in a statement released on Tuesday that the attack reported large scale casualties.
“The hospital was operational, with patients, health and care givers, and internally displaced people sheltering there.
“Early reports indicate hundreds of fatalities and injuries,” it said.
According to the statement, the hospital is one of 20 in the north of the Gaza Strip facing evacuation orders from the Israeli military.
It said that the order for evacuation had been impossible to carry out given the current insecurity and critical condition of many patients.
It said that other problems were lack of ambulances, staff, health system bed capacity, and alternative shelter for those displaced.
The statement called for the immediate active protection of civilians and health care.
”Evacuation orders must be reversed.
“International humanitarian law must be abided by, which means health care must be actively protected and never targeted,” it said.
The UN Secretary-General, Antonio Guterres also condemned the strike on Al Ahli Anglican Episcopal Hospital in Gaza, with preliminary reports of hundreds killed and many others wounded, including women and children.
He also condemned the attack on a UN Palestine refugee agency (UNRWA) school in Al-Maghazi refugee camp in Gaza which killed at least six people.
UN spokesperson, Stephane Dujarric, said this in a statement on Tuesday.
Dujarric said the secretary-general extended his sincere condolences to the families of the victims and wishes a swift recovery to those injured.
He emphasised that hospitals, clinics, medical personnel, and UN premises were explicitly protected under international law.