Israeli air raids in the Gaza Strip killed more than a dozen people overnight into Saturday morning, hospital and local authorities said, as health workers were wrapping up the second phase of an urgent polio vaccination campaign designed to prevent a large-scale outbreak in the territory.

The vaccination drive was launched after health officials confirmed the first polio case in the Palestinian enclave in 25 years, in a 10-month-old boy whose leg is now paralysed. The nine-day campaign run by the UN health agency and its partners began last Sunday in central Gaza and aims to vaccinate 640,000 children under the age of 10, an ambitious effort during a devastating war that has destroyed Gaza's health care system and much of its infrastructure.

The second phase of vaccinations in the southern part of the strip was in its final day Saturday, the Gaza Health Ministry said, before moving to the north and concluding on Monday. The ministry designated dozens of points across the southern cities of Khan Younis and Rafah for people to visit with their children to receive the vaccines.

Israel meanwhile kept up its military offensive. In central Gaza's urban refugee camp of Nuseirat, Al-Awda Hospital said it had received the bodies of nine people killed in two separate air raids. One had hit a residential building in the early hours of Saturday, killing four people and wounding at least 10, the hospital said, while another five people were killed in a strike on a house in the western part of Nuseirat.

Separately, Al-Aqsa Martyrs Hospital, central Gaza's main hospital in the town of Deir al-Balah, said a woman and her two children were killed in another strike on a house in the nearby urban refugee camp of Bureij early Saturday. In the northern part of the Gaza Strip, an airstrike on a school-turned-shelter for displaced people in the town of Jabaliya killed at least four people and wounded about two dozen others, according to Gaza's Civil Defence authority, which operates under the territory's Hamas-run government.

The war began when Hamas and other militants staged a surprise attack on Israel on Oct. 7, killing around 1,200 people, primarily civilians. Hamas is believed to still be holding more than 100 hostages. Israeli authorities estimate about a third are dead.

Israel's retaliatory offensive has killed more than 40,000 Palestinians, according to the Health Ministry in Hamas-controlled Gaza, which doesn't distinguish between civilians and combatants in its count. The ministry reports more than 94,000 people have been wounded since the start of the war.

Violence has also spiked in the occupied West Bank, with a more than weeklong military operation in the town of Jenin leaving dozens of dead and a trail of destruction.

On Friday, a 13-year-old girl and an American protester were reported shot and killed in separate incidents in the West Bank.

Aysenur Ezgi Eygi, 26. of Seattle, who also holds Turkish nationality, died after being shot in the head on Friday, two Palestinian doctors said. Witnesses to the shooting said she had posed no threat to Israeli forces and was shot during a moment of calm following clashes earlier in the afternoon.

The White House has said it was “deeply disturbed” by the killing and has called on Israel to investigate. The Israeli military said it was looking into reports that troops had killed a foreign national while firing at an “instigator of violent activity” in the area of the protest.

Separately, Palestinian health officials said Israeli fire had killed a 13-year-old girl, Bana Laboom, in the West Bank village of Qaryout, south of Nablus, on Friday.

The Israeli military said on Saturday that an “initial inquiry indicates” security forces had been deployed to disperse a riot involving Palestinian and Israeli civilians that “included mutual rock hurling.” The security forces had fired shots in the air, the military said.

“A report was received regarding a Palestinian girl who was killed by shots in the area. The incident is under review,” the military added.

There are more than 500,000 Israeli settlers living in the West Bank, a territory captured by Israel in 1967. Increasing Israeli raids, attacks by Palestinian militants on Israelis and attacks by Israeli settlers on Palestinians have left more than 690 Palestinians dead since the Israel-Hamas war began in October, according to Palestinian health officials.

Israel has been under increasing pressure from the United States and other allies to reach a cease-fire deal in Gaza, but Prime Minister Benjamin Netanyahu insists on a demand that has emerged as a major sticking point in talks — continued Israeli control of the Philadelphi corridor, a narrow band along Gaza's border with Egypt where Israel contends Hamas smuggles weapons into Gaza. Egypt and Hamas deny it.

Hamas has accused Israel of dragging out months of negotiations by issuing new demands, including for lasting Israeli control over both the Philadelphi corridor and a second corridor running across Gaza.

Hamas has offered to release all hostages in return for an end to the war, the complete withdrawal of Israeli forces and the release of a large number of Palestinian prisoners, including high-profile militants — broadly the terms called for under an outline for a deal put forward by US President Joe Biden in July.