Hospital officials in northern Gaza say many people have been killed in overnight Israeli airstrikes.
Gaza rescue teams say search operations began early in the morning after Israel bombed at least five buildings in Beit Lahia and Gaza City.
According to Hamas-oriented media, dozens of people have been killed and many remain buried under the rubble, including women and children.
There was no immediate comment from the Israeli military. It has recently intensified its offensive in northern Gaza, saying it is preventing Hamas from regrouping.
Parts of northern Gaza are under siege by Israel and virtually no humanitarian aid has been provided in forty days, the UN previously warned.
Gaza doctors say they are struggling to treat the wounded, while aid groups say they are unable to get essential supplies to the area.
Earlier this week, at least 34 people were killed in an Israeli airstrike on a five-storey residential block in Beit Lahia, the local civil defense agency said.
The agency, quoted by AFP news agency, said many of the dead were women and children.
Israel’s ground offensive in northern Gaza has displaced up to 130,000 people in the past five weeks.
The UN says 75,000 people remain under siege with dwindling water and food supplies in the cities of Beit Lahia, Jabalia and Beit Hanoun.
Last week’s Human Rights Watch report said Israel committed war crimes and crimes against humanity by deliberately causing the mass displacement of Palestinians in Gaza.
About 1.9 million people – 90% of Gaza’s population – have fled their homes in the past year and 79% of the territory is under Israeli-issued evacuation orders, the UN said.
Israel launched a campaign to destroy Hamas in response to the group’s unprecedented attack on southern Israel on October 7, 2023, which killed around 1,200 people and took 251 others hostage.
Nearly 44,000 people have been killed and more than 104,000 injured in Gaza since then, according to the Hamas-run Health Ministry.
On Wednesday, the US blocked a draft resolution for a ceasefire in Gaza at the UN Security Council – the fourth time the country has used its veto to protect its ally, Israel, during the conflict.
Fourteen of fifteen council members voted in favor of the draft, which demanded that the war in Gaza “end immediately, unconditionally and permanently and that all remaining hostages be released immediately and unconditionally.”
The deputy US ambassador to the UN, Robert Wood, said the document “neglected” the need for a “link between a ceasefire and the release of hostages”.
Wood said the proposed resolution would have sent a “dangerous message” to Hamas.
In a separate development, American mediator Amos Hochstein has arrived in Israel from Beirut.
He has said he sees a “real opportunity” to end the conflict in Lebanon after the Lebanese government and Hezbollah largely agreed to a US ceasefire proposal.
