Israel announced Sunday its troops had found six dead hostages in a Gaza tunnel, while Israeli police said a "shooting attack" in the occupied West Bank killed three officers.
In the besieged Gaza Strip, "humanitarian pauses" in the nearly 11-month war between Israel and Hamas were set to take hold on Sunday to facilitate a massive polio vaccination drive which a health official told AFP had begun.
The deadly shooting near the city of Hebron added to surging violence in the West Bank, which is separated from Gaza by Israeli territory and where Israeli forces pressed on with a large-scale military operation that sparked international concern.
A military statement said the remains of six hostages were recovered Saturday "from an underground tunnel in the Rafah area" in southern Gaza and formally identified in Israel.
The were named as Carmel Gat, who was taken from a kibbutz community near the Gaza border, and Hersh Goldberg-Polin, Eden Yerushalmi, Almog Sarusi, Ori Danino and Alexander Lobanov – a dual Russian-Israeli national – who were seized by Palestinian militants from the site of a rave party.
Military spokesman Daniel Hagari said all six "were abducted alive on the morning of Oct. 7" and "brutally murdered by Hamas terrorists shortly before we reached them."
U.S. President Joe Biden, whose administration has been involved in mediation efforts to secure a Gaza truce and hostage release deal, said he was "still optimistic" that a deal can be reached.
"It's time this war ended", Biden told reporters, and in a statement said he was "devastated and outraged" by the deaths of the six hostages, including U.S.-Israeli Goldberg-Polin.
The six were among 251 hostages seized during Hamas's Oct. 7 attack that triggered the ongoing war, 97 of whom remain captive in Gaza including 33 the Israeli army says are dead. Scores were released during a negotiated one-week truce in November.
'Delays and excuses'
Campaign group the Hostages and Missing Families Forum said a negotiated "deal for the return of the hostages" was urgently needed.
"Were it not for the delays, sabotage and excuses" in months of mediation efforts, the six hostages "would likely still be alive."
Critics in Israel have accused Prime Minister Benjamin Netanyahu of prolonging the war for political gain.
Senior Hamas official Izzat Rishq, without elaborating on the circumstances of the six hostages' death, blamed the Israeli "occupation ... which continues its genocidal war" and "runs away from a cease-fire deal."
Netanyahu said Hamas leaders were the ones "who kill hostages and do not want an agreement," vowing to "settle the score" with them.
U.S. Vice President Kamala Harris, the Democratic candidate in upcoming elections to replace Biden, said Goldberg-Polin – seen alive in a video released by his captors in April – "was murdered by Hamas."
Harris in a statement said the "evil" Palestinian group has "American blood on its hands," and that "the threat Hamas poses to the people of Israel ... must be eliminated and Hamas cannot control Gaza."
Hamas's Oct. 7 attack resulted in the deaths of 1,205 people, mostly civilians, according to an AFP tally based on Israeli official figures.
Israel's offensive has killed at least 40,691 people in Gaza, according to the territory's health ministry. The U.N. rights office says most of the dead are women and children.
The fighting has devastated Gaza, repeatedly displaced most of its 2.4 million people and triggered a humanitarian crisis. Water, sanitation and medical facilities have been ravaged, contributing to the spread of preventable disease.
Following the first confirmed polio case in 25 years, a Gaza health official said vaccinations began Saturday ahead of a wider campaign.
The World Health Organization has said Israel agreed to a series of three-day "humanitarian pauses" to facilitate the vaccination drive.
On Sunday, the campaign was formally launched at three health centers in central Gaza with Palestinians arriving with their children for a dose of the vaccine, said Yasser Shaabane, director of Al-Awda Hospital.
"We hope this vaccination campaign for children will be calm," said Shaabane, noting there were "a lot of drones flying over" the area.
The civil defense agency said an Israeli air strike killed two people in Gaza City, further north, where an AFP correspondent reported artillery shelling early Sunday.
West Bank violence
As fighting rages on in Gaza, Israeli forces and Palestinian militants were battling in the West Bank, five days into major coordinated Israeli raids which the military has described as "counter-terrorism" operations.
A "shooting attack" near Tarqumiya checkpoint in the Hebron area in the southern West Bank killed three people on Sunday, said Israel's emergency medical service. The police force later said they were all officers.
In the northern West Bank, an AFP photographer saw Israeli bulldozers in Jenin's city center, a day after a local official said soldiers had destroyed most of the streets while power and water had been cut off in the adjacent Jenin refugee camp.
At least 22 Palestinians, including 14 claimed by militant groups, have been killed by the Israeli military since Wednesday in simultaneous raids in several cities across the northern West Bank.
Israel's military said a 20-year-old soldier was killed Saturday.
Britain, France and Spain have all expressed concerns about Israel's West Bank operation.
Jordanian Foreign Minister Ayman Safadi said that "Israel alone is responsible for the dangerous escalation", urging an end to "its bloody aggression on the occupied West Bank."
The United Nations said Wednesday that at least 637 Palestinians had been killed in the territory by Israeli troops or settlers since the Gaza war began.
Twenty-three Israelis, including soldiers, have been killed in Palestinian attacks or during army operations over the same period, according to Israeli official figures.