Clashes rocked the West Bank on Thursday as thousands attended the funerals of a prisoner and two teenagers shot dead by Israeli troops and Palestinian president Mahmud Abbas said the killings jeopardised US efforts to rekindle peace talks.

Israeli soldiers fired rubber bullets in the southern city of Hebron after furious crowds lined the streets to pay their respects to 63-year-old Maisara Abu Hamdiyeh, whose body was carried in a cortege to a local mosque for burial. Abu Hamdiyeh, who had served 10 years of a life term for attempted murder, died of throat cancer on Tuesday in hospital, sparking tension on the Palestinian street and its leadership accusing Israel of medical negligence. As news of his death spread, protests that erupted in several places quickly turned into clashes with the Israeli army, notably in Hebron, Abu Hamdiyeh's home town.

Near the northern village of Anabta close to Tulkarem, the clashes turned deadly, with two teenagers shot dead overnight by troops, Israeli and Palestinian sources said. Palestinian security officials said Amer Nasser, 17, was killed by a bullet to the head and Naji Balbisi, 19, whose body was discovered at dawn, was shot in the chest.

The Israeli military said troops had opened fire at "rioters who hurled petrol bombs" at a military post. Abbas slammed the killings, saying in a statement that "the Israeli government is behind this escalation. "The Israeli government is responsible for the (negative) impact on US and international efforts to restart negotiations." He charged in a separate speech to his Fatah party that "Israel is trying to ignite chaos," adding that "there's no way peaceful demonstrations should lead to two deaths."

His remarks come just days ahead of a visit by US Secretary of State John Kerry, who will hold fortnightly meetings with Israeli and Palestinian leaders, local media say, as he tries to revive the stalled Middle East peace process.In Anabta, where schools and shops were closed in mourning, around 6,000 people gathered for the funerals, many calling for revenge as the two bodies arrived, both wrapped in Palestinian flags, an AFP correspondent said.

Maath Kanaan spoke bitterly about the loss of his friend Amer. "He always had a nationalist spirit and he was the first one to go to demonstrations. They killed him in cold blood," he said.Since news of Abu Hamdiyeh's death emerged, Hebron has been wracked by clashes between stone-throwing youths and Israeli troops, and since Tuesday the city has been shut down for a three-day general strike in a show of mourning.

Soldiers on Thursday erected roadblocks in Hebron's old city and fired rubber bullets at protesters who set tyres alight.On Wednesday, 4,600 prisoners in Israeli jails staged a one-day hunger strike, with another 1,900 refusing breakfast again on Thursday, the prisons service said.Abu Hamdiyeh was jailed for life in 2002 on charges of attempted murder in connection with a failed bomb attack on a Jerusalem cafe. He had served 10 years of his sentence when he died.

The issue of Palestinians jailed by Israel is highly sensitive, and frequently sparks mass demonstrations across the territories that often flare into violent clashes with the military.In the Gaza Strip, Salafist fighters fired a handful of rockets over the border in protest on Tuesday and Wednesday, prompting retaliatory air strikes. Prime Minister Benjamin Netanyahu warned that if a current truce in and around Gaza was violated, Israel would "respond forcefully."

In a separate development, Israel has reportedly deployed a fifth battery of its vaunted Iron Dome anti-missile system in the southern city of Eilat, over fears of rocket fire on the Red Sea resort.Meanwhile, US Secretary of State John Kerry is headed back to the Middle East for his third trip in a month, foraging for signs that Israel and the Palestinians are ready to make tough sacrifices for peace.

In a surprise move, the State Department announced Wednesday that Kerry will return to Jerusalem and the Palestinian territories early next week to build on a series of talks last month between American and regional leaders.Expectations are growing that the US administration is ready to resume some kind of shuttle diplomacy to rekindle the moribund peace process, which has stalled since late 2010 amid bitter recriminations on both sides. But State Department spokeswoman Victoria Nuland cautioned: "I would not expect the secretary to be putting down a plan."

President Barack Obama visited Israel and the West Bank in mid March, with Kerry then staying behind in the region to meet separately with both Israeli Prime Minister Benjamin Netanyahu and Palestinian president Mahmud Abbas.

"They've had some time to reflect on the visit," Nuland said. "So this a chance for the secretary to go back and to listen again and to hear what they think is possible." "But he'll also be making clear that the parties themselves have to want to get back to the table, that this is a choice that they have to make, and that they've also got to recognize, both parties, that compromise and sacrifices are going to have to be made if we're going to be able to help."