An Israeli airstrike on a refugee camp in northern Gaza killed at least 33 people, including 21 women, the Strip's Hamas-run authorities said.
There was no immediate comment on the reported attack on Jabalia from Israel, whose forces have besieged the densely populated camp for weeks.
The killing of Hamas leader Yahya Sinwar this week raised hopes in some quarters for an end to the war, but the group's deputy leader said Hamas would only get stronger.
US President Joe Biden said there was an opportunity to "work towards a ceasefire" in Lebanon, where Israel is fighting Hezbollah militants, but it would be "difficult in Gaza".
He was speaking as he left the German capital Berlin, where he met with German, French and British leaders.
According to a statement from Gaza's Hamas-run government media office, Friday's airstrikes injured more than 85 people, some seriously, as the homes of three families in the camp were damaged.
The final death toll could reach 50, it added, as people were buried under the rubble of buildings.
The report could not be independently verified. Local sources indicate that northern Gaza is effectively isolated, with telecommunications and internet services cut off in the region.
A video circulating on social media - which News has not verified - shows a body wrapped in a white shroud in the courtyard of Al-Awda Hospital.
The hospital director spoke to reporters about the overwhelming influx of casualties.
"Ambulance crews are still trying to rescue the martyrs and injured from Jabaliya," the director said.
"Our hospital wards are completely full and many injured people are being treated on the floor."
According to news agency Reuters, the Hamas-run health ministry in Gaza said at least 39 Palestinians were killed in Israeli strikes on Friday, many of them in Jabalia, before the latest attack.
About 400,000 people have been trapped inside the camps for more than two weeks with little food or water.
The head of the UN humanitarian aid office, Georgios Petropoulos, told the News Hour program that families in Jabaliya were enduring "brutal conditions".
"We cannot sound enough alarm bells about how dire and dangerous the situation is for civilians there," he said, speaking from Rafah in southern Gaza.
Israel said it had sent about 30 lorries of supplies including food, water, medical supplies and shelter equipment to northern Gaza on Friday, but local health officials told Reuters that aid had not reached the worst-hit areas, such as Jabalia.
Israel has repeatedly denied it is blocking humanitarian aid from entering Gaza but the US has asked it to increase access or risk cutting off some US military aid.
An Israeli minister, Amichai Chikli, told News that Israel has "besieged" parts of northern Gaza, including Jabalia.
"We allowed the civilian population to escape to safe areas, and we blocked the entry of supplies into the besieged area," he told the News Hour programme.
He insisted it was "legal under international law".
Since Hamas-led attacks on Israel just over a year ago, at least 42,500 people have been killed and tens of thousands wounded in Gaza, Hamas-run authorities say.
About 1,200 people were killed and 251 taken hostage in Gaza by Hamas and its allies in the 7 October 2023 attack.
On Friday, Hamas deputy leader Khalil al-Hayya said the Israeli hostages would not be returned until Israel ends the war and withdraws from Gaza.
Sinwar was blamed for the October 7 attack. He was killed in a firefight after "tank fire" hit the building he was hiding in in the southern Gaza city of Rafah, according to the Israeli military.
The Israeli pathologist who performed the autopsy told US media that he had been shot in the head.
Dr. Chen Kugel also suffered injuries to his right arm from "missile fire," a damaged left leg from "fallen masonry," and shrapnel injuries.
//Source: BBC News//