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 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.

Hamas, the 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 poured into the streets in the territory, chanting in solidarity with Jenin.

Internationally-backed Palestinian President Mahmoud Abbas declared three days of mourning and ordered flags at half-staff.

Palestinian Authority spokesman Nabil Abu Rudeineh 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 United Nations 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.

Thursday’s gun battle erupted when the Israeli military conducted a rare daytime operation in the refugee camp that it said was meant to prevent an imminent attack against 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 but 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.

In Jenin, the raid left a trail of destruction.

A two-storey building, apparently the target of the operation, was a charred wreck.

The military said it entered the building to detonate the suspects’ alleged 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 relocating 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 facilitate their operation, which may have complicated rescue efforts, and that tear gas had likely wafted into the hospital from the clashes nearby.

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.

-AAP