Israel carried out heavy bombardments in the Gaza Strip on Sunday as international pressure mounted for greater protection of civilians and the renewal of an expired truce deal with Palestinian militant group Hamas.

The prospect of another cease-fire in Gaza appeared bleak, as Israel recalled its negotiators and Hamas' deputy leader said any further swap of hostages for Palestinians imprisoned by Israel would only happen as part of ending the conflict.

The Israeli army said it had conducted more than 400 strikes in Gaza since the truce deal collapsed on Friday, including more than 50 in Khan Younis and its surrounding areas in the south. Hamas said at least 240 Palestinians were killed in the offensive.

Israeli strikes also hit the Nuseirat refugee camp in central Gaza on Saturday, killing at least 13 people, according to the official Palestinian news agency Wafa.

United States Vice-President Kamala Harris, who is in the United Arab Emirates to attend the COP28 global climate conference, sharply criticized on Saturday the rising civilian toll in Israel's eight-week offensive, sparked by an unprecedented Hamas attack on Israel on Oct 7.

The overall death toll in Gaza had surpassed 15,200 as of Saturday, with 70 percent of the dead being women and children, according to Hamas.

"Too many innocent Palestinians have been killed," Harris told reporters in Dubai. "Frankly, the scale of civilian suffering and the images and videos coming from Gaza are devastating."

An estimated 1.7 million Gaza residents — more than two-thirds of its population — have been displaced by the conflict, according to the United Nations. On Sunday, Tedros Adhanom Ghebreyesus, director-general of the World Health Organization, said on X, formerly Twitter, that he couldn't "find words strong enough to express our concern over what we're witnessing".

The Palestine Red Crescent Society said that Israel had told NGOs not to bring aid convoys across the Rafah border crossing from Egypt after the truce expired. As a result, Gaza residents are once again grappling with shortage of food, water and daily necessities.

Biden losing support

In the US, Muslim community leaders from several swing states pledged on Saturday to withdraw support for President Joe Biden at a conference in suburban Detroit, citing his refusal to call for a cease-fire in Gaza. They said the community's support for Biden is waning as more Palestinian men, women and children are killed in Gaza.

The weeklong truce, brokered with the help of Qatar and Egypt, led to the release of 80 Israeli hostages in exchange for 240 Palestinian prisoners. But the deal collapsed with both sides blaming each other for violating its conditions. Israel said that Hamas had tried to fire a rocket before the cease-fire ended, and that it had failed to produce a list of further hostages for release.

Israel's Defense Minister Yoav Gallant told reporters on Saturday that fresh military action was needed to "create the conditions that push (Hamas) to pay a heavy price".

French President Emmanuel Macron appealed for "stepped-up efforts to reach a lasting cease-fire "to free all hostages, allow in more aid and to assure Israel of its security. He said he was heading to Qatar to work on a new truce deal.

Macron took issue with Israel's stated war aims, warning that if the "total destruction of Hamas" in Gaza was the goal, "the war will last 10 years".

AGENCIES — XINHUA