An 85-year-old Israeli freed after more than two weeks of captivity by Hamas militants in war-torn Gaza said on Tuesday "I went through hell" during her abduction. 

International pressure has built for the release of the more than 200 other Israeli and foreign nationals still trapped inside Gaza amid withering Israeli bombardment sparked by the deadly Hamas attacks of October 7.

Israel was left stunned and furious by the bloody attack on southern communities in which it says Hamas killed more than 1,400 people and took the hostages, whose families have endured an agonising wait since.

Israel has responded with heavy air and artillery strikes that have killed 5,791 in Gaza, according to the Hamas-ruled health ministry, and plunged the Palestinian territory into a dire humanitarian crisis.

US President Joe Biden, speaking earlier in Washington, allowed for the possibility of a ceasefire if the other captives are freed, saying: "We should have those hostages released and then we can talk."

French President Emmanuel Macron, on a solidarity visit to Israel, also stressed that getting the hostages out alive is "the first objective".

He condemned as an "awful crime" the militants' hostage operation and willingness "to play with the lives of children, adults, old people, civilians and soldiers".

One of two elderly hostages freed late Monday, Yocheved Lifshitz recounted how the militants "went on a rampage in our kibbutz, kidnapped me, lay me over a motorcycle... and sped off with me through the ploughed fields".

They "beat me on the way - they didn't break my ribs but hurt me very much," said Lifshitz, seated in a wheelchair and surrounded by media at a Tel Aviv hospital.

She was freed with Nurit Cooper, 79, by Hamas, which cited "compelling humanitarian" reasons, after mediation by Qatar and Egypt, days after a US mother and her teenage daughter were also released.

During her weeks of captivity, Lifshitz said, "they treated us well," describing her captors as courteous and saying a doctor visited every two to three days.

Lifshitz, whose husband remains in Hamas captivity, said the militants appeared to have "prepared for a long time" to take large numbers of hostages.

"They had everything that men and women needed including shampoo," she told journalists. "We ate the same food they did - pitas with cream cheese, melted cheese, cucumbers."

Dire need in Gaza

Prime Minister Benjamin Netanyahu has vowed to destroy Hamas and warned of a looming ground invasion of Gaza, raising the spectre of heavy urban combat and heightening the risk for the hostages.

Macron, speaking after talks with Netanyahu in Jerusalem, proposed that the international coalition still fighting the Islamic State group "should also fight against Hamas."

The coalition set up in 2014 says it has 86 members including nation states, the European Union and the Arab League. It has focused on countering IS remnants in Iraq and Syria but aims to cut funding and support for them in many countries.

Macron also stressed the need for a "decisive relaunch" of the Palestinian peace process, ahead of a planned visit to Palestinian president Mahmud Abbas in Ramallah in the occupied West Bank.

The Hamas surprise attack, which left Israel reeling and enraged, led it to launch operation "Swords of Iron" in which it has fired a near-continuous barrage of strikes on Gaza, where Hamas said 140 people were killed overnight.

Thousands of buildings have been destroyed in the densely populated enclave, with entire city blocks reduced to rubble and many victims still feared buried beneath.

Gaza City resident Ayman Abu Shamalah was among the tens of thousands who heeded an Israeli warning to flee the north of the territory but this did not spare his family from tragedy.

An Israeli air strike on Rafah in southern Gaza killed his pregnant wife as well as their three-year-old son and nine-year-old daughter, he told AFP tearfully.

"They put my son's shattered body in a blue bag," he said.

UN human rights chief Volker Turk on Monday urged an "immediate humanitarian ceasefire" for Gaza where about half of the population of 2.4 million has been driven from their homes.

Israel has cut off water, food, fuel and energy supplies to Gaza, and only a trickle of aid has been allowed in from Egypt in recent days under a US-brokered deal.

The UN World Health Organisation warned that more than one-third of Gaza's hospitals were "not functioning" and limited fuel supplies were impacting ambulances in the territory, where thousands have been wounded.

Tunnel labyrinth

Israel has shown little sign of slowing its looming offensive, although the timing of an anticipated full-scale ground invasion remains unclear. 

Hamas has built a labyrinth of tunnels which the Israeli military has darkly dubbed the "Gaza Metro" and its fighters would be expected to meet invading forces with booby traps, assault rifles and grenade launchers, spelling costly house-to-house fighting.

Macron also stressed that the campaign must be fought without "enlarging this conflict" as concern has grown about more of Israel's enemies across the Middle East entering the war.

The US-based Institute for the Study of War has reported a rise in attacks on Israeli and US targets from Iranian-backed groups in Lebanon, Iraq and Yemen.

There have been daily exchanges of cross-border fire between Israel and Lebanon's Iran-backed Hezbollah militant group.

At least 41 people have been killed in Lebanon, according to an AFP tally - mostly combatants but also at least four civilians, including a Reuters journalist. And four people have been killed in Israel - three soldiers and a civilian.