Abbas announced "public mourning for three days and flags flown at half-mast for the martyrs of the Baptist hospital massacre and all our people's martyrs", the official Palestinian news agency Wafa said.

The media office of Gaza's Hamas government described the attack as a "war crime".

"The hospital was housing hundreds of sick and wounded, and people forcibly displaced from their homes" because of other strikes, a statement said.

The attack on the al-Ahli Al-Arabi Hospital in Gaza City would be by far the deadliest Israeli airstrike in five wars fought since 2008.

"We cannot meet the needs, and the massacre is significant." Spokesperson for the Gaza Civil Defense told the media adding that most of the victims are patients and children.

Several hospitals in Gaza City have become refuges for hundreds of people, hoping they would be spared bombardment after Israel ordered all residents of the city and surrounding areas to evacuate to the southern Gaza Strip.

Israeli military spokesman Rear Adm. Daniel Hagari said there were still no details on the hospital deaths: “We will get the details and update the public. I don’t know to say whether it was an Israeli air strike.”

In the south, Israeli airstrikes killed dozens of civilians and at least one senior Hamas figure Tuesday as U.S. officials worked to convince Israel to allow delivery of supplies to desperate civilians, aid groups and hospitals after days of failed hopes for an opening in the siege.

Around 3,000 people have been killed in Israeli air strikes across the Gaza Strip since the war erupted on 7 October.