The city of Khan Younis in southern Gaza, where thousands of civilians moved from the north of the enclave, came under intense bombardment on Friday, when the weeklong truce expired, and intensified on Saturday.

Clouds of grey smoke from the strikes hung over Gaza, where the Hamas-run Ministry of Health said more than 190 people had been killed and hundreds were wounded in renewed Israeli bombardment.

Israel said its ground, air and naval forces struck more than 400 targets in Gaza in its latest attacks. It also called on people to evacuate from Khan Younis as it expands its military operations, urging them to move southwards towards Rafah, close to the border with Egypt.

Each of the warring sides blamed the other for the truce collapse by rejecting terms to extend the daily release of hostages held by Hamas fighters in exchange for Palestinians held in Israeli jails.

‘Hell on Earth’

The United Nations said the fighting would worsen the extreme humanitarian emergency in Gaza.

“Hell on Earth has returned to Gaza,” said Jens Laerke, spokesperson for the UN humanitarian office in Geneva.

“Today, in a matter of hours, scores were reportedly killed and injured. Families were told to evacuate, again. Hopes were dashed,” said UN aid chief Martin Griffiths, adding that children, women and men of Gaza had “nowhere safe to go and very little to survive on”.

A pause that started on November 24 had been extended twice and Israel had said it could continue as long as Hamas released 10 hostages each day. But after seven days – during which women, children and foreign hostages were freed – mediators failed to find a formula to release more.

Israel accused Hamas of refusing to release all the women it held. A Palestinian official said the breakdown occurred over female Israeli soldiers.

Al Jazeera’s Hind Khoudary in Deir el-Balah in Gaza said Israeli tanks have not stopped shelling the enclave and the gunboats are attacking the coastline of the Strip.

“It was very tough last night with people in Gaza describing it as one of the toughest, as there has been non-stop bombardment in the last 24 hours,” she said.

“Houses have been targeted. At least three mosques were hit. Areas across the Gaza Strip – the north, south and centre, have all been targeted.”

Israel has sworn to annihilate Hamas after an October 7 rampage in which it says the group killed about 1,200 people and took 240 hostage.

Israeli assaults since have laid waste to much of Gaza, ruled by Hamas since 2007. Palestinian health authorities deemed reliable by the United Nations say more than 15,000 Gazans, including 6,150 children, have been killed and thousands are missing.

Qatar, which has played a central mediating role, said negotiations were continuing with Israelis and Palestinians to restore the truce, but Israel’s renewed bombardment of Gaza had complicated matters.

Israel says its priority is to get as many hostages released as possible as it puts military pressure on Hamas.

Officials say Hamas released 110 hostages during the truce – 86 Israelis and 24 foreigners – in exchange for a total of 240 Palestinian prisoners. At the same time, Israel detained almost as many Palestinians in East Jerusalem and the West Bank.

‘Israel wants buffer zone’

US officials told The Wall Street Journal newspaper that Washington provided Israel with large “bunker buster” bombs, among tens of thousands of other weapons and artillery shells, to help dislodge Hamas from Gaza.

Meanwhile, Israel has informed several Arab states that it wants to carve out a buffer zone on the Palestinian side of Gaza’s border to prevent future attacks, Egyptian and regional sources, quoted by the Reuters news agency, said.

The report said that Israel related its plans to its neighbours Egypt and Jordan, along with the United Arab Emirates, which normalised ties with Israel in 2020.

There has also been a renewed escalation of hostilities on Israel’s Syrian and Lebanese borders after the truce in Gaza ended.

Syrian air defences repelled an Israeli rocket attack against targets in the vicinity of Damascus early on Saturday, according to Syrian state media, which added that most of the missiles were shot down.

Separately, casualties were reported in southern Lebanon, with Lebanon state media reporting that Israeli shelling killed three people on Friday.

The Iran-backed Lebanese group Hezbollah, a Hamas ally, said two of those killed were its fighters. It added it had carried out several attacks on Israeli military positions at the border.