Police briefly detained a Jewish settler from Hebron who allegedly talked of killing Prime Minister Ariel Sharon (search), police said Monday, while hundreds of Palestinian students there protested to demand that a college Israel shut down be reopened.

Hebron (search) is West Bank flashpoint where about 550 Jewish settlers live in three enclaves, surrounded by more than 130,000 Palestinians.

Israel closed Hebron's Polytechnic Institute in January, saying students belonging to militant groups like Hamas (search) and Islamic Jihad (search) had used its facilities to plan and carry out attacks. About 400 students marched on the Palestinian Authority office in Hebron, calling on leaders to work to reopen the college.

A 22-year-old Jewish man from Hebron was arrested Sunday outside Sharon's Jerusalem residence after he told security officials, "The prime minister killed my friend and my neighbor. It's no problem at all for me to kill him," according to police spokeswoman Zvia Cohen. She said the man was a resident of Hebron's Jewish enclaves, but did not give his name.

He was released Monday pending a police investigation and after pledging not to return to Jerusalem for 15 days, police said. Police have not decided whether to file charges.

Hebron settlers' spokesman David Wilder said the man's comments likely referred to Elazar Leibovitz, a soldier killed by Palestinian militants in an ambush near Hebron in July 2002, and to 10-month-old Shalhevet Pass, shot dead by a sniper in March 2001.

Hard-liners among the settlers have complained that Sharon is not tough enough against the militants.

"He said something very stupid, something which shouldn't be said," Wilder said. "But knowing him and his family, it was a remark made without any intention of carrying this act out."

Hebron's Jewish enclave is a center for ultranationalist Jews. Earlier this month, two Jewish settlers from the Hebron area were charged with possessing explosives stolen from the army, apparently in connection with an anti-Arab plot. One of them is Yitzhak Pass, father of the dead baby.

Security around Israel's prime minister was stepped up in May following threats from right-wing Jews to punish him for his support of the U.S.-sponsored "road map" peace plan. In 1995, Israeli Prime Minister Yitzhak Rabin was assassinated by an Israeli Jew opposed to his efforts to promote Israeli-Palestinian reconciliation.

Meanwhile, peace efforts appeared stalled despite a Palestinian cease-fire that has brought a sharp reduction in the violence that raged for three years

On Sunday, Israel slammed on the brakes, with Sharon and other officials saying the plan would not move ahead until the Palestinians dismantled militant groups.

The Palestinians said Israel was the one violating the blueprint.

Sharon made it clear during the Cabinet meeting that there can be "no progress toward a Palestinian state without full implementation of their obligations," said an Israeli official who briefed reporters on condition of anonymity.

Under the road map, the Palestinians are supposed to dismantle "terrorist capabilities and infrastructure (including) confiscation of illegal weapons."

Palestinian Prime Minister Mahmoud Abbas refuses to order a crackdown on militants, fearing a civil war, and wants to persuade the militants to end their attacks.

As part of the plan, Israel commits to dismantle about 100 unauthorized settlement outposts established in the West Bank since 2001, take steps to help normalize Palestinian life and withdraw "progressively" from Palestinian autonomous zones occupied since fighting between the two sides erupted in September 2000.

Israel has so far withdrawn from parts of the Gaza Strip and from the West Bank town of Bethlehem. About a dozen outposts have been taken down, but a similar number have gone back up. Some roadblocks have been removed, but dozens remain.

The official said that at Sunday's Cabinet meeting, military chief of staff Lt. Gen. Moshe Yaalon said Palestinian security forces were doing little or nothing to stop attacks.

"The Palestinian Authority must dismantle the terrorist infrastructure -- period," the official quoted Yaalon as saying.

Palestinian legislator Saeb Erekat said it was Israel, rather than the Palestinians, which was failing to live up to its commitments under the road map, which is meant to lead to Palestinian statehood by 2005.

"In accordance with the road map, what should be dismantled is the Israeli occupation and the Israeli settlements," Erekat told The Associated Press.