Despite intensive negotiations, mediators were unable to get the warring sides to agree to an extension of a 72-hour humanitarian ceasefire that ended on Friday, with rocket fire out of Gaza beginning almost immediately and Israel responding with air strikes soon after.

Both the US and the United Nations condemned the renewed attacks, with Secretary-General Ban Ki-moon appealing to both sides to not undertake further military action “that can only exacerbate the already appalling humanitarian situation in Gaza".

White House spokesman Josh Earnest urged both parties to work towards a "sustainable ceasefire".

"Hamas' decision to resume rocket fire will not only put the people of Israel and of Gaza at greater risk, it will do nothing to meet the expectations of the Palestinian people," Mr Earnest said.

Palestinians want Israel to lift the air, sea and land blockade of Gaza that for the past seven years has severely restricted the movement of both people and goods in and out of the coastal enclave, leaving it in the grip of a worsening humanitarian crisis.

Egypt has also been asked to open its border with Gaza, which has been operating under severe restrictions, although it is understood Egyptian officials have insisted the focus of the talks should be the dispute between Israel and Hamas.

Other key demands include the release of prisoners held in Israeli jails and the opening of a sea port, Hamas spokesman Sami Abu Zuhri said.
Israel is demanding that militant groups in Gaza disarm – a call rejected by Hamas – who says it is willing to continue the talks despite the resumption of violence.

Five Palestinians, including three children, were killed in renewed Israeli air strikes on Friday, and houses and mosques were destroyed in central and northern Gaza, local authorities reported.

The Israel Defence Forces said it had resumed its offensive with aircraft, tanks and navy shelling on “70 terror sites” in response to at least 40 rockets fired into southern Israel since the truce ended.

"The renewed rocket attacks by terrorists at Israel are unacceptable, intolerable and short-sighted,” said Israel Defence Forces spokesman Lieutenant Colonel Peter Lerner.

Despite the renewed military activity – which was subdued compared to the past four weeks – rescue teams continued to recover bodies still buried beneath the rubble of homes and buildings across Gaza.

A UN spokesman said 32 new fatalities were reported on Friday, including 11 children and eight women, taking the death toll in Gaza to 1888 people, 446 of them children, since Israel began its military operations on July 8. Israel has lost 66 soldiers, while three civilians, including one Thai national, have also been killed.

Meanwhile, Amnesty International has called for Israel to be referred to the International Criminal Court over mounting evidence that its military launched "apparently deliberate attacks against hospitals and health professionals in Gaza" that resulted in the deaths of six medics.

“The harrowing descriptions by ambulance drivers and other medics of the utterly impossible situation in which they have to work, with bombs and bullets killing or injuring their colleagues as they try to save lives, paint a grim reality of life in Gaza,” said Philip Luther, Middle East and North Africa director at Amnesty International.

“Even more alarming is the mounting evidence that the Israeli army has targeted health facilities or professionals. Such attacks are absolutely prohibited by international law and would amount to war crimes.”

The talks in Cairo are expected to continue on Saturday.