YITZHAR, West Bank - A new dynamic has emerged in the West Bank: Jewish settlers block roads, burn tires or set fire to Palestinian fields when troops try to dismantle unauthorized settlements.

Activists call the tactic "price tag." They hope the havoc will deter Israeli security forces from removing any of the dozens of squatter camps, or outposts, dotting West Bank hills. But outgoing Prime Minister Ehud Olmert warned Sunday that an "evil wind of extremism" is threatening Israel's democracy.

Without naming any specific group, Olmert complained that extremists are undermining "the ability of those in charge in Israel to make decisions."

The comments to the Israeli cabinet and a pipe bomb attack that wounded a prominent Israeli critic of the settlers added to the debate about the dangers of ultra-nationalists.

Despite Sunday's forceful words, Olmert and his predecessors failed to live up to a 2003 promise to the U.S. to take down dozens of outposts. Critics of the government also say Israeli police and military often ignore settler violence.

"The radical extremists in the right-wing camp understand that the government is just too afraid to confront them," said Yariv Oppenheimer, leader of the settlement watchdog group Peace Now.

The nearly 300,000 West Bank settlers are a heterogeneous group. They range from suburbanites in settlements near Israel, who moved to the West Bank for cheaper housing, to ideologues and radical "hilltop youth" who believe Israel must keep the territory for religious and security reasons.

The ideological settlers feel betrayed by Israel's 2005 pullout from Gaza, including the evacuation of some 8,500 settlers, and are determined to prevent a repeat in the West Bank.

Hardliners have been gaining ground against the more pragmatic leaders of the settlers' umbrella group, the Yesha Council, which has been negotiating with the government over the fate of the outposts.

Two large regional councils, Samaria and Binyamin in the northern West Bank, last year elected leaders who oppose any compromise on the outposts.

Firebrand activist Daniella Weiss and regional settler leader Yitzhak Shadmi said it includes blocking roads and demonstratively entering Arab villages. "If this makes the security forces crazy, so be it," said Shadmi, a lieutenant colonel in the army reserves.

Both drew the line at attacking Palestinians or their property, but said they wouldn't dissuade others who advocate more extreme action.

Noam Federman, a well-known radical settler from the southern West Bank, said the tactic has been used at least four times so far, most recently on Sept. 18, after the removal of a small outpost, Yad Yair.

On Sept. 18, protesters punctured tires of army vehicles at the outpost. Later, Israelis set fire to fields near two Palestinian villages and torched a Palestinian home near Ramallah, the military and villagers said.

A June ad in a local newspaper of the Kedumim settlement also described the tactic. "During the removal (of a trailer from an outpost), roads were blocked in the area, and later many fires erupted," said the ad, signed by the Residents' Committee of the Samaria Regional Council.

"This is a true example of how the boundaries of the struggle are determined by the settlers," the ad said.

The Israeli human rights group Yesh Din has reported an increase in settler attacks on Israeli soldiers and Palestinians in recent months.

This comes in the context of years of Israeli-Palestinian fighting in the West Bank, including hundreds of attacks against settlers and periodic attempts by armed Palestinians to infiltrate Israeli settlements.

One of the hotspots is the Yitzhar settlement, overlooking the West Bank Palestinian villages of Assira al-Kubliyeh, Burin and Madameh.

Burin Mayor Ali Eid recited a list of settler attacks in recent months, including the burning of hundreds of trees and the firebombing of a house. A chunk of metal the size of a toaster sat on a table in his office, a fragment from one of nine projectiles he said have been fired at Burin.

Two weeks ago, Yitzhar settlers went on a rampage in Assira al-Kubliyeh, following an arson and stabbing attack that injured a nine-year-old boy from the settlement. Dozens of stone-throwing settlers, some firing in the air, smashed windows of several homes and overturned a car in the village. Six villagers were hurt, including a 17-year-old girl shot in the right arm. Yesh Din said Israeli soldiers did little to prevent the riot.

Police say they're still investigating and have not made arrests.

A week later, Israeli troops shot dead a 14-year-old Palestinian from Assira as he lit a firebomb near Yitzhar. Police say he was the assailant from the week before.

Yitzhar has long been considered a hotbed of militancy, an image the settlement's spokesman, Yigal Amitay, accepts with pride. "Yitzhar will always prefer to be in the position of the aggressor and not in the position of the victim," said the 42-year-old father of 10, sitting in his garden along a quiet street lined with small cottages.

The settlement has spawned six outposts where 45 of Yitzhar's 170 families live.

Officials would not comment on the new tactic, but government spokesman Mark Regev said vigilantes would not be tolerated and police say there have been some arrests.

The Settlers' Council is still trying to get a better grasp of the "price tag" tactic, said a member, Sara Eliash. In principle, she said, "it is very grave that people decide to exact a price from the state of Israel."