Israel resumed its deadly bombardment of Gaza on Friday, saying it struck more than 200 targets in the densely-inhabited Palestinian territory despite international calls for a renewed truce.

The Hamas-run health ministry said that at least 109 people had been killed in Gaza since the pause in hostilities expired in the morning and ground battles and Israel air strikes resumed.

Israel alleged that Hamas had attempted to break the truce even before it ended at 0500 GMT by firing a rocket, and that it had failed to produce a list of hostages that could have been released on Friday in exchange for Palestinian prisoners.

But both the United Nations chief and the White House called for the break in fighting to be restored, and UN agencies warned of a "catastrophic" humanitarian situation as bombs fell and hospitals again struggled to cope with the wounded after a week-long respite.

"We continue to work with Israel, Egypt, and Qatar on efforts to extend the humanitarian pause in Gaza," a White House National Security Council spokesperson said, after US Secretary of State Antony Blinken left Israel following diplomatic efforts to shore up the truce.

In a social media post, United Nations Secretary-General Antonio Guterres said: "I deeply regret that military operations have started again in Gaza. I still hope that it will be possible to renew the pause that was established."

Gaza like 'horror movie'

Under the truce, Hamas militants released hostages in exchange for Palestinian prisoners held in Israeli jails, and greater aid flows into war-devastated Gaza.

But with explosions audible and a dark column of smoke rising over northern Gaza, Israel's army said its warplanes were striking Hamas targets across the Palestinian territory and AFP journalists saw, and visited the aftermath, of several bombings.

Outgoing missiles fired by Palestinian groups towards Israel were also seen. 

"The healthcare service is on its knees," Rob Holden, a World Health Organisation (WHO) senior emergency officer, told journalists in Geneva on a video-link from Gaza as explosions were heard in the background. "It is like a horror movie."

Israeli officials, however, took a tough line, insisting Hamas was to blame for the new eruption of fighting and vowing to destroy the Islamist movement.

"Unfortunately, Hamas decided to terminate the pause by failing to release all the kidnapped women," Israeli government spokesman Eylon Levy told reporters. "Having chosen to hold onto our women, Hamas will now take the mother of all thumpings."

The Israeli military said: "Over the last few hours, ground, air and naval forces struck terror targets in the north and south of the Gaza Strip, including in Khan Yunis and Rafah." 

Combat resumed shortly after Israel's army said it had intercepted a rocket fired from Gaza, the first from the territory since a missile launched minutes into the truce on November 24.

In the rubble of a house destroyed by bombs in the southern Gaza city of Rafah, a man screamed: "Where are my children?"

In Khan Yunis, a group of men chanted "God is greatest" as they rushed through the streets carrying a body wrapped in a white shroud. War has returned, even more fiercely", Anas Abu Dagga, 22, told AFP.

Talks 'ongoing'

On a bed at Khan Yunis's Nasser hospital, a member of the same family, Amal Abu Dagga wept, her beige veil covered in blood.

"I don't even know what happened to my children," she said. Another relative, Jamil Abu Dagga, told AFP the family had been at home when the bombs started falling.

In Israel, sirens warning of potential missiles sounded in several communities near Gaza, and authorities said they were restarting security measures in the area including closing schools.

A rocket strike destroyed a van in one Israeli community near Gaza.

The office of Israeli Prime Minister Benjamin Netanyahu said fighting had restarted after Hamas violated the truce.

"The Government of Israel is committed to achieving the goals of the war: Releasing the hostages, eliminating Hamas and ensuring that Gaza never again constitutes a threat to the residents of Israel," it said.

Despite the resumption of fighting, talks between Qatari and Egyptian mediators were "ongoing", said a source briefed on the talks.

During the seven-day truce, Hamas freed 80 Israeli hostages in exchange for 240 Palestinian prisoners, and more aid entered Gaza, where 1.7 million people are displaced and short of food, water and other essentials, according to the United Nations.

Twenty-five other hostages, mostly Thais, were also freed during the truce but outside the scope of its terms.

On Thursday, Washington's top diplomat Antony Blinken, meeting Israeli and Palestinian officials, called for the truce to be extended, and warned any resumption of combat must protect Palestinian civilians.

Other world leaders, and aid groups, had also sought an extended pause in the fighting that began on October 7 when Hamas militants broke through Gaza's militarised border into Israel.

During the unprecedented attack, Hamas killed about 1,200 people, mostly civilians, and kidnapped around 240, according to Israeli authorities.

In response, Israel vowed to eliminate Hamas and unleashed an air and ground military campaign in Gaza that the Hamas authorities who run Gaza say has killed more than 15,000 people, also mostly civilians.

'Evacuation zones'

On Thursday eight more Israeli hostages, some holding dual nationality, were released.

Not long after the hostages arrived in Israel, the country's prison service said another 30 Palestinian prisoners — 23 minors and seven women — had been freed.

Hamas said it had also offered to hand over the bodies of a mother and her two sons — one of them a baby — in talks to extend the now-expired truce.

Shiri Bibas, her 10-month-old son Kfir and his four-year-old brother Ariel, along with their father Yarden, have become emblematic of the October 7 attacks due to the age of baby Kfir. Israeli officials refused to comment on Hamas "propaganda".

The Israeli military published a map of "evacuation zones" in the Gaza Strip. The military said it would enable residents to "evacuate from specific places for their safety if required".

Residents in multiple areas were sent SMS warnings on Friday.

Israeli forces "will begin a crushing military attack on your area of residence with the aim of eliminating the terrorist organisation Hamas," the warnings said. 

"Stay away from all military activity of every kind."