DOHA/CAIRO/JERUSALEM - Israel intensified strikes on Gaza hours after a ceasefire and hostage release deal was announced, residents and authorities in the Palestinian enclave said, as mediators sought to quell fighting ahead of the truce's start on Sunday.

The complex ceasefire accord between Israel and militant group Hamas, which controls Gaza, emerged on Wednesday after months of mediation by Qatar, Egypt and the US and 15 months of bloodshed that devastated the coastal territory and inflamed the Middle East.

The deal outlines a six-week initial ceasefire with the gradual withdrawal of Israeli forces from the Gaza Strip, where tens of thousands have been killed. Hostages taken by Hamas would be freed in exchange for Palestinian prisoners detained by Israel.

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At a news conference in Doha, Qatari Prime Minister Sheikh Mohammed bin Abdulrahman Al Thani said the ceasefire would take effect on Sunday. Negotiators are working with Israel and Hamas on steps to implement the agreement, he said.

"This deal will halt the fighting in Gaza, surge much-needed humanitarian assistance to Palestinian civilians, and reunite the hostages with their families after more than 15 months in captivity," US President Joe Biden said in Washington.

His successor, Donald Trump, takes office on Monday and claimed credit for the breakthrough in Gaza.

Israel's acceptance of the deal will not be official until it is approved by the country's security cabinet and government, with votes slated for Thursday, an Israeli official said.

The accord was expected to win approval despite opposition from some hardliners in Israeli Prime Minister Benjamin Netanyahu's coalition government.

Significant progress was made in the negotiations once the Biden and Trump administrations began working hand-in-hand to make the case for urgency, outgoing US Ambassador to Israel Jack Lew told Reuters.

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While people celebrated the pact in Gaza and Israel, Israel's military escalated attacks after the announcement, the civil emergency service and residents said.

Heavy Israeli bombardment, especially in Gaza City, killed 32 people late on Wednesday, medics said. The strikes continued early on Thursday and destroyed houses in Rafah in southern Gaza, Nuseirat in central Gaza and in northern Gaza, residents said.

Israel's military said Gaza militants fired a rocket into Israel on Thursday, causing no casualties

Jubilation in Gaza

In social media posts, some Gaza residents urged Palestinians to exercise extra caution in the belief Israel could step up attacks in the next few days to maximize gains before the ceasefire starts.

Nevertheless, news of the ceasefire deal sparked jubilation in Gaza, where Palestinians have faced severe shortages of food, water, shelter and fuel. In Khan Younis, throngs clogged the streets amid the sounds of horns as they cheered, waved Palestinian flags and danced.

"I am happy. Yes, I am crying, but those are tears of joy," said Ghada, a displaced mother of five.

In Tel Aviv, families of Israeli hostages and their friends likewise welcomed the news, saying in a statement they felt "overwhelming joy and relief (about) the agreement to bring our loved ones home".

In a social media statement announcing the ceasefire, Hamas called the pact "an achievement for our people" and "a turning point".

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If successful, the ceasefire will halt fighting that has razed much of heavily urbanized Gaza, killed over 46,000 people and displaced most of the tiny enclave's pre-war population of 2.3 million, according to Gaza authorities.

That in turn could defuse tensions across the wider Middle East, where the war has stoked conflict in the Israeli-occupied West Bank, Lebanon, Syria, Yemen and Iraq, and raised fears of all-out war between arch regional foes Israel and Iran.

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With 98 Israeli hostages remaining in Gaza, phase one of the deal entails the release of 33 of them, including all women, children and men over 50. Two American hostages, Keith Siegel and Sagui Dekel-Chen, were among those to be released in the first phase, a source said.

Food lined up at the Gaza’s borders

The agreement calls for a surge in humanitarian assistance to Gaza, and the UN and the International Committee of the Red Cross said they were preparing to scale up their aid operations.

Global reaction to the ceasefire was enthusiastic. Leaders and officials of Egypt, Türkiye, Britain, the United Nations, the European Union, Jordan, Germany and the United Arab Emirates, among others, celebrated the news.

Biden and Trump both claimed credit for the deal that was months in the making but was helped across the line by a Trump emissary.

Trump's Mideast envoy Steve Witkoff was in Qatar along with White House envoys for the talks, and a senior Biden administration official said Witkoff's presence was critical to reaching a deal after 96 hours of intense negotiations.

Biden said that the two teams had "been speaking as one".

Israeli hostage families expressed concern that the accord may not be fully implemented and some hostages may be left behind in Gaza.

Negotiations on implementing the second phase of the deal will begin by the 16th day of phase one, and this stage was expected to include the release of all remaining hostages, a permanent ceasefire and the complete withdrawal of Israeli forces from Gaza.

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The third stage is to address the return of all remaining dead bodies and the start of Gaza's reconstruction supervised by Egypt, Qatar and the United Nations.

If all goes smoothly, the Palestinians, Arab states and Israel must still agree on a vision for post-war Gaza, including the unanswered question of who will run Gaza after the war.

Israeli troops invaded Gaza after Hamas-led gunmen burst into Israeli border-area communities on Oct 7, 2023, killing 1,200 soldiers and civilians and abducting over 250 hostages, according to Israeli tallies.