Israel kept up its air strikes on Gaza on Wednesday after Prime Minister Benjamin Netanyahu vowed to ramp up the pressure on Hamas as hopes fade for a United States-announced ceasefire plan.

Hamas political leader Ismail Haniyeh accused Israel of deliberately undermining negotiations for a truce and hostage release deal because it did not want to end the war.

The Israeli military said it had carried out 25 strikes in 24 hours, targeting "military structures, infrastructure, cells and rigged structures".

It said its troops were also "continuing precise, intelligence-based operational activity" around the southern Gaza city of Rafah.

Netanyahu, who has repeatedly vowed to destroy Hamas, insisted Tuesday that despite the pressure Israel was coming under, there could be no let-up in Israel's campaign against the group.

"This is exactly the time to increase the pressure even more, to bring home all the hostages - the living and the dead - and to achieve all the war objectives," he said.

The Health Ministry in Hamas-ruled Gaza said 52 people, most of them women and children, had been killed in Israeli strikes over the previous 24 hours.

The UN humanitarian office OCHA said multiple strikes across Gaza on Tuesday killed and wounded dozens.

The territory's civil defence agency said 30 people had been killed in three strikes in Nuseirat refugee camp in central Gaza, one on a United Nations-run school, another on a house and a third on a mosque.

In southern Gaza, two people were killed in Israeli bombardment of the Shakush area, northwest of Rafah, a medical source at Nasser Hospital said.

At least 90 per cent of Gazans have been forced from their homes, many of them seeking refuge in UN-run schools. Seven of them have been hit by Israeli strikes since July 6.

Nearly 70 per cent of UN-run schools across Gaza have been hit during more than nine months of fighting, the UN agency for Palestinian refugees (UNRWA) said on Tuesday.

"Why do they target us when we are innocent people?" asked Umm Mohammed al-Hasanat, sheltering with her family at a UN-run school in Nuseirat, which was among those hit.

"We do not carry weapons but are just sitting and trying to find safety for ourselves and our children."

Washington has been pushing for a truce deal between Israel and Hamas since President Joe Biden released details of what he said was an Israeli ceasefire roadmap on May 31.

But despite the efforts of Egyptian and Qatari mediators, indirect negotiations between the foes have made no headway.

In a telephone call with Turkish Foreign Minister Hakan Fidan late Tuesday, the Hamas leader blamed Israel for the deadlock.

"We dealt positively with the proposals put to us by the mediators but the occupation (referring to Israel) is avoiding the required outcome and does not want to reach an agreement under which it ends its war," Haniyeh said.

His comments came after a senior Hamas official said on Sunday that the group was withdrawing from the current talks following Israel's deadly strikes but was ready to return if its attitude changes.

The war began with Hamas' unprecedented Oct 7 attack on Israel which resulted in the deaths of 1,195 people, mostly civilians, according to an AFP tally based on Israeli figures.

The group also seized 251 hostages, 116 of whom are still in Gaza including 42 the Israeli military says are dead.

Israel responded with a military offensive that has killed at least 38,713 people, also mostly civilians, according to figures from the Gaza Health Ministry.

Critics in Israel, including tens of thousands of demonstrators who have taken to the streets to demand a deal to bring home the hostages, have accused Netanyahu of prolonging the war.

The families of five Israeli women soldiers among the hostages said Tuesday they were "begging" the prime minister to "make the deal happen".

"We are waiting for a face-to-face meeting with you (Netanyahu) to ensure that the negotiations are moving towards a signed deal," said Ayelet Levy, whose daughter was abducted on Oct 7.

Meanwhile, ultra-Orthodox Jewish protesters fought police near Tel Aviv, hours after the Israeli military said it would begin issuing draft notices for men in the community from Sunday.

Historically exempt from compulsory military service, ultra-Orthodox seminary students are being called up as the Gaza war and a potential conflict with Hizbollah strain the armed forces' manpower and fuel resentment against those who do not have to serve. AFP

  - AFP