The deadliest single operation in the territory in two decades prompted Palestinian leaders to cut security ties with Israel, a move that could lead to more violence.

The Israeli military also fatally shot a 22-year-old Palestinian later in a separate incident.

The raid in the Jenin refugee camp increases the risk of a major flare-up in Israeli-Palestinian fighting, poses a test for Israel's new hard-line government and casts a shadow on US Secretary of State Antony Blinken's expected trip to the region next week.

Raising the stakes, the Palestinian Authority said it would halt the ties that its security forces maintain with Israel in a shared effort to contain Islamic militants. Previous such efforts have been short-lived, in part because of the benefits the authority enjoys from the relationship and also due to US and Israeli pressure to maintain it.

The PA already has limited control over scattered enclaves in the West Bank, and its forces have little authority in militant strongholds like the Jenin camp. But the announcement could pave the way for Israel to step up operations it says are needed to prevent attacks.

Hamas, the Islamist militant group that controls Gaza, threatened revenge for the raid. Violent escalations in the West Bank have previously triggered retaliatory rocket fire from the Gaza Strip.

Israeli forces in the West Bank and on the country's border with Gaza went on heightened alert. Protesters filled the streets in the territory, chanting in solidarity with Jenin. Palestinians in the refugee camp dug a mass grave for the dead and Abbas declared three days of mourning.

Nabil Abu Rudeineh, a spokesman for the Palestinian Authority, said Abbas had decided to cut security coordination in “light of the repeated aggression against our people, and the undermining of signed agreements," referring to commitments from the Oslo peace process in the 1990s.

He also said that the Palestinians planned to file complaints with the UN Security Council, International Criminal Court and other international bodies.

The PA last cut security coordination with Israel in 2020, over Prime Minister Benjamin Netanyahu's drive to annex the occupied West Bank, which would render a future Palestinian state unviable. But six months later, the PA resumed cooperation, signalling the financial importance of the relationship and the Palestinians' relief at the election of President Joe Biden.

Barbara Leaf, the top US diplomat for the Middle East, said the administration was deeply concerned about the situation and said civilian casualties reported in Jenin were “quite regrettable”. But she also said the Palestinian announcement to suspend security cooperation with Israel was a mistake.

“Obviously, we don't think this is the right step to take at this moment,” she told reporters, saying the Palestinian vow to bring the matter to the UN and the International Criminal Court was problematic.

“We want to see them move back in the other direction," she said, adding: "They need to engage with each other.”

Thursday's gunbattle erupted when Israel's military conducted a rare daytime operation in the refugee camp that it said was meant to prevent an imminent attack on Israelis. The camp, where the Palestinian Islamic Jihad militant group has a major foothold, has been a focus of near-nightly Israeli arrest raids.

At least one of the dead was identified by Palestinians as a militant; it was not clear how many others were affiliated with armed groups.

Later in the day, Israeli forces fatally shot a 22-year-old, the Palestinian Health Ministry said, as Palestinians confronted Israeli troops north of Jerusalem to protest Thursday's raid.

Tensions have soared since Israel stepped up raids in the West Bank last spring, following a series of Palestinian attacks.

Israel's new national security minister, far-right politician Itamar Ben-Gvir, who seeks to grant legal immunity to Israeli soldiers who shoot Palestinians, posted a video of himself beaming triumphantly. He congratulated security forces, saying the government gives “backing to our fighters in the war against the terrorists.”

The raid left a trail of destruction in Jenin. A two-story building, apparently the operation's target, was a charred wreck. The military said it entered the building to detonate explosives.

Palestinian Health Minister May Al-Kaila said paramedics struggled to reach the wounded during the fighting, while Akram Rajoub, the governor of Jenin, said the military prevented emergency workers from evacuating them.

Both accused the military of firing tear gas at the pediatric ward of a hospital, causing children to choke. Video at the hospital showed women carrying children into a corridor.

The military said forces closed roads to aid the operation, which may have complicated rescue efforts, and that tear gas had likely wafted into the hospital from nearby clashes.

The Palestinian Health Ministry identified the 61-year-old woman killed as Magda Obaid, and the Israeli military said it was looking into reports of her death. Health officials identified the eight other dead as men ranging in age from 18 to 40. The Al-Aqsa Martyrs' Brigade — an armed militia affiliated with Fatah, the secular political party that controls the Palestinian Authority — claimed one of the dead, Izz al-Din Salahat, as a fighter. The ministry said at least 20 people were wounded.

According to Israeli rights group B'Tselem, May 14, 2021, was the deadliest day in the West Bank since 2002, with 13 Palestinians killed that day in confrontations. But Thursday marked the single bloodiest incursion since 2002, during an intense wave of violence known as the Second Intifada, or Palestinian uprising, which left scars still visible in Jenin.

“We ask that the international community help the Palestinians against this extremist right-wing government and protect our citizens,” said Rajoub, the Jenin governor.

UN Middle East envoy Tor Wennesland said he was “deeply alarmed and saddened” by the violence. Condemnations came from the Organisation of Islamic Cooperation and Turkey, which recently reestablished full diplomatic ties with Israel, as well as from neighbouring Jordan.

Saudi Arabia criticized the raid, saying it rejected the “serious violations of international law by the Israeli occupation forces.” Qatar called it a “brutal Israeli aggression” and an “extension of the heinous and horrific crimes of the occupation against the defenseless Palestinian people.” Kuwait and Oman added condemnations.

Tensions over West Bank violence have spilled into Gaza before.

“The response of the resistance to what happened today in Jenin camp will not be delayed,” warned top Hamas official Saleh Arouri.

The Islamic Jihad branch in the coastal enclave has repeatedly fought against Israel, most recently in a fierce three-day clash last summer that killed dozens of Palestinians and disrupted the lives of hundreds of thousands of Israelis.

Nearly 150 Palestinians were killed in the West Bank and east Jerusalem last year, making 2022 the deadliest in those territories since 2004, according to B'Tselem. So far this year, 30 Palestinians have been killed.

Israel says most of the dead were militants. But youths protesting the incursions and others not involved in the confrontations also have been killed. So far this year, not including Thursday, one-third of the Palestinians killed by Israeli troops or civilians had ties to armed groups.

Last year, 30 people were killed in Palestinian attacks against Israelis.

Israel says its raids are meant to dismantle militant networks and thwart attacks. The Palestinians say they further entrench Israel's 55-year, open-ended occupation of the West Bank, which Israel captured along with east Jerusalem and the Gaza Strip in the 1967 Mideast war. The Palestinians claim those territories for their hoped-for state.

Israel has established dozens of settlements in the West Bank that now house 500,000 people. The Palestinians and much of the international community view settlements as illegal and an obstacle to peace, even as talks to end the conflict have been moribund for over a decade.?