An Israeli air strike on a five-storey residential block in Beit Lahia in northern Gaza has killed at least 34 people, the local civil defence agency says.
The agency, quoted by AFP, said many of the dead were women and children, with dozens stilled feared to be under the rubble. Seven people were also injured.
The Israeli military said it had been striking militant targets in the northern Gaza, including Beit Lahia, in an attempt to stop Hamas from regrouping.
Elsewhere, in central Gaza three separate attacks on refugee camps killed 15 people, while five more were killed in a Israeli drone attack on Rafah in the south, the civil defence added.
"The chances of rescuing more wounded are decreasing because of the continuous shooting and artillery shelling," civil defence spokesman Mahmud Bassal said.
All that is left of the residential building in Beit Lahia is a pile of rubble, with broken concrete and jagged shards of twisted metal sticking out from the ruins.
One man, whose family lived in the flattened building, but was staying elsewhere, said, quoted by AFP: "We all thought that death was near."
"The whole area was shaking."
The Israeli military said its offensive in northern Gaza - which began in Jabalia and expanded into Beit Lahia - consisted of several strikes overnight on what it called "terrorist targets in the area".
It added in a statement that "there have been continuous efforts to evacuate the civilian population from the active war zone".
But many local residents do not want to leave their homes. Mr Bassel said six families had lived in the razed building in Beit Lahia.
One woman in the area vented her frustration to BBC News.
"What have we done to you people? What harm have we caused you? What wrong have we committed? We are staying in our homes. Why are you driving us out?”
Last week, at least 25 people, including 13 children were killed in a strike on a house in Jabalia. In Gaza City, another five were killed.
Israel's ground offensive in northern Gaza has displaced up to 130,000 people over the past five weeks.
The United Nations says 75,000 people remain under siege with dwindling supplies of water and food in the towns of Jabalia, Beit Lahia and Beit Hanoun.
A report by Human Rights Watch this week said Israel had 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 over the past year, and 79% of the territory is under Israeli-issued evacuation orders, according to the UN.
Israel launched a campaign to destroy Hamas in response to the group's unprecedented attack on southern Israel on 7 October 2023, in which about 1,200 people were killed and 251 others were taken hostage.
More than 43,700 people have been killed in Gaza since then, according to the territory's Hamas-run health ministry.