Israel pummelled Gaza for a 14th day on Monday, hiking the Palestinian death toll to more than 570, as Cairo took centre stage in world efforts to broker a ceasefire.

With air strikes and shelling raining down across the besieged coastal enclave, Israel's army said seven of its soldiers had been killed, bringing the Israeli toll to 25 troops and two civilians in the bloodiest Gaza conflict since 2009.

Washington urged Israel to take "greater steps" to prevent innocent casualties, and UN chief Ban Ki-moon appealed for the violence to "stop now" as it emerged most of the dead were civilians.

But Hamas has so far rejected truce calls, insisting Monday on a lifting of Israel's siege of Gaza and the release of prisoners to cease its rocket fire.

Arab League chief Nabil al-Arabi urged Hamas to accept an Egyptian proposal to end the fighting it had rejected last week.

Speaking in Cairo where he had arrived to advance a truce, US Secretary of State John Kerry pledged $47 million in humanitarian aid to Gaza as he called for an end to the violence.

"We are deeply concerned about the consequences of Israel's appropriate and legitimate effort to defend itself," he told reporters as he met with the UN chief.

Both Kerry and Ban urged Hamas, the dominant force in the Gaza Strip, to accept the Egyptian-proposed ceasefire.

Monday's attacks across Gaza killed at least 56 people including 16 children, bringing the overall death toll since Israel launched its operation on July 8 to 573 Palestinians, according to figures provided by Gaza emergency services spokesman Ashraf al-Qudra.

In the costliest single Israeli bombardment, an air strike hit a residential tower block in central Gaza City, killing 11 people, including five children.

It came after Israeli tank shells struck a hospital in Deir al-Balah, killing four people, including doctors, officials said, indicating at least 70 people were wounded.

Rights group Amnesty International warned Monday that the shelling of the hospital as well as the "continuing bombardment of civilian homes" in Gaza "add to the list of possible war crimes that demand an urgent independent international investigation."

Amnesty said the Israeli attacks on civilian areas in Gaza "as well as the continuing indiscriminate rocket attacks on Israel, demand urgent international action to prevent further violations."

Israel says its campaign aims to stamp out rocket fire from Gaza, and the ground phase of the operation to destroy tunnels burrowed into Israel by Hamas, the main power in the coastal strip.

Israeli rights group B'Tselem said that initial findings indicated that 25 members of the same family were killed Sunday night northeast of Khan Yunis by Israeli fire seeking a senior Hamas member.

"Information B'Tselem has at this stage indicates that no warning was issued and no warning missile was fired prior to the attack," the group said.

100,000 displaced

Since the Israeli operation began on July 8, huge numbers of Gazans have fled their homes, with the UN saying more than 100,000 people have sought shelter in 69 schools run by its Palestinian refugee agency (UNRWA).

Meanwhile, Israeli forces killed more than 10 Gaza fighters who had infiltrated southern Israel, the army said, later announcing it had lost four soldiers in that battle.

The troops lost in that clash were among seven killed in 24 hours, said the Israeli army, adding 30 soldiers were wounded over the same period.

That brought its toll to 25 soldiers killed since the start of the operation, including 13 on Sunday, the bloodiest single day for the Israeli military since the Lebanon war of 2006.

Two Israeli civilians, both hit by rocket fire, have been killed during the 14-day campaign.

'Mad war'

Hamas on Monday reiterated its insistence on a lifting of Israel's blockade of Gaza and the release of prisoners to halt its rocket fire.

"The conditions for a ceasefire are... a full lifting of the blockade and then the release of those recently detained in the West Bank," its leader in Gaza, Ismail Haniya, said on television.

"We cannot go backwards, to a slow death," he said, referring to the Israeli blockade in force since 2006.

"The conditions of the Palestinian resistance constitute the minimum required for a truce. The resistance and the sons of our people who have made such sacrifices in this mad war cannot accept anything less."

Meanwhile, Hamas leader Khaled Meshaal and Palestinian president Mahmud Abbas held talks in Doha, pledging to work together for a ceasefire and to lift the blockade on Gaza.

But there has been no let-up since the operation began with 116 rockets hitting Israel on Monday, one striking the greater Tel Aviv area, and another 17 shot down, the army said.

Violence also broke out in the West Bank, where an Israeli shot dead a Palestinian who had been throwing stones at his car, Palestinian security sources said.

An Israeli army spokeswoman said the military was investigating the death, which she said took place during "a violent riot".

Israeli police said Palestinians had rioted in east Jerusalem neighbourhoods Monday night, with no casualties.

Elsewhere in the West Bank, an Israeli was seriously wounded after a Palestinian opened fire at him from a travelling car, the army said.