Israeli strikes hammered a Gaza refugee camp on Friday after a deadly strike on a UN-run school, as the war sparked by Hamas's unprecedented attack on Israel entered its ninth month.
The conflict has killed tens of thousands, laid waste to much of the Gaza Strip, uprooted most of its 2.4 million population and put them at risk of starvation.
Diplomatic efforts to mediate the first ceasefire since a week-long pause in November appear to have stalled, only a week after US President Joe Biden offered a new three-stage roadmap.
Hamas, which has ruled the Gaza Strip since 2007, has yet to respond to Biden's proposal. Israel has expressed openness to discussions while insisting on pursuing its war aim of destroying the Palestinian Islamist group.
Al-Aqsa Martyrs hospital in Deir al-Balah in central Gaza said at least 37 people were killed in Thursday's Israeli strike on the UN-run school in Nuseirat camp.
The Israeli army said its fighter jets killed nine "terrorists" in three classrooms where about 30 militants from Hamas and Islamic Jihad had been hiding.
The United Nations agency for Palestinian refugees, UNRWA, said hundreds of displaced Palestinians had been sheltering at the school which was "hit without prior warning".
UN Secretary-General chief Antonio Guterres described the strike as "another horrific example of the price that civilians are paying".
The United States, which provides Israel with $3.8 billion in annual military aid, urged its ally to be "fully" transparent about the strike.
"The government of Israel has said that they are going to release more information about this strike, including the names of those who died in it. We expect them to be fully transparent in making that information public," said State Department spokesman Matthew Miller.
Israel accuses Hamas and its allies in Gaza of using schools, hospitals and other civilian infrastructure including facilities run by UNRWA, the UN agency for Palestinian refugees, as operational centres -- charges the militants deny.
On Friday, strikes targeted various areas across the Gaza Strip.
A day after the school was hit, the Nuseirat refugee camp faced renewed Israeli artillery shelling and air strikes, eyewitnesses said.
A medical source at Al-Aqsa Martyrs hospital said the Isa family home near a medical centre in the Bureij refugee camp was targeted, leaving several wounded.
Witnesses also confirmed Israeli strikes in the east of Deir al-Balah, as well as intensive fire from Israeli army vehicles east of the Bureij camp, where a blaze raged at a roundabout.
In Gaza City, casualties were reported from an Israeli missile strike on the Ashram family home near Al-Salam mosque, according to a medical source at Baptist Hospital.
Six people were killed and several wounded in an Israeli strike on the Wafati home in Maghazi camp, said a medical source at Al-Aqsa Martyrs hospital.
Air force jets also targeted the Al-Sultan neighbourhood of Rafah, sources in the city on the southern border with Egypt said.
Gaza also came under fire from the sea, with Israeli warships bombarding homes in the fishermen's port area, among others, west of Gaza City, an AFP correspondent said.
The war was sparked by Hamas's October 7 attack, which resulted in the deaths of 1,194 people, mostly civilians, according to an AFP tally based on Israeli official figures.
Militants also took 251 hostages, 120 of whom remain in Gaza, including 41 the army says are dead.
Israel's retaliatory military offensive has killed at least 36,654 people in Gaza, also mostly civilians, according to the Hamas-run territory's health ministry.
Israel has faced growing diplomatic isolation, with international court cases accusing it of war crimes and several European countries recognising a Palestinian state.
Spain, which last week sparked Israeli fury by formally recognising Palestinian statehood, said Thursday it would become the latest country to join South Africa's case at the International Court of Justice accusing Israel of "genocide" against Palestinians in Gaza.
Israeli Prime Minister Benjamin Netanyahu has meanwhile accepted an invitation from lawmakers in the United States to address Congress on July 24, a congressional source told AFP.
A week ago, Biden outlined what he labelled an Israeli plan to halt the fighting for six weeks while hostages are exchanged for Palestinian prisoners in Israeli jails and the delivery of aid into Gaza is stepped up.
G7 powers and Arab states have backed the proposal, with 16 world leaders joining Biden's call for Hamas to accept the deal.
"There is no time to lose. We call on Hamas to close this agreement," the joint statement said.
Egypt's state-linked Al-Qahera news quoted a high-level source on Thursday saying Cairo had "received positive signs from the Palestinian movement signalling its aspiration for a ceasefire".
But the Beirut-based senior Hamas official Osama Hamdan later cast doubt on the proposal, calling it "just words".
Qatar's foreign ministry spokesman said on Thursday that Hamas has not yet given its response on the truce plan.
Major sticking points include Hamas insisting on a permanent truce and full Israeli withdrawal -- demands Israel has rejected.
The war has caused tensions to soar across the Middle East, with increased violence between Israel and its allies on one side, and Iran-backed armed groups on the other.
The Israeli military on Thursday announced a soldier was killed in a drone strike by Lebanon's Iran-backed Hezbollah militant group the day before on Hurfeish.
Netanyahu was in the occupied West Bank on Thursday, a day after saying Israel was "prepared for a very intense operation" along the border with Lebanon.
"The state of Israel is in a difficult campaign on many fronts," he said. "This effort is being carried out amid complicated international pressure on us."
The US State Department's Miller has said any "escalation" in Lebanon would "greatly harm Israel's overall security".