Avi Ben Yakov is a soft-spoken Jewish settler who loves playing with his young children in their red-roofed home in the hills above Nablus, deep inside the West Bank. But when it comes to his Palestinian neighbors, his tone hardens.

"They will not be my neighbors if I do what I have to do, which is take them back to their lands," he said. "We don't want them here. Expelling them is the solution."

Ben Yakov would not say if he had been personally involved in a series of recent attacks on the nearby Palestinian village of Asira Al-Qibiliyya. But he said the violence was justified by the Israeli army's failure to protect the lives and property of West Bank settlers.

Such frustration has been growing in recent months, and the result has been a pronounced rise in settler attacks on Palestinians, according to military officials, human rights groups and settler organizations. While only a small proportion of settlers are involved, the attacks reflect a deep-felt anxiety that Israel may be nearing a decision to abandon some of its West Bank settlements, much in the same way it withdrew from its Gaza Strip settlements three years ago. Settlers unwilling to leave their homes say they are ready to fight for them, even if that means battling their erstwhile ally, the Israeli army.

"In the past, only a few dozen individuals were implicated in this. Today, we're talking about several hundred people -- a very significant change," Maj. Gen. Gadi Shamni, the Israeli officer responsible for security in the West Bank, recently told the Haaretz newspaper. "An extreme incident could happen at any time. These people are conspiring against the Palestinians and against the security forces."

The human rights group B'Tselem lists 429 reported settler attacks on Palestinians this year -- an increase of 75 percent over last year. In Asira al-Qibiliyya, the Palestinian village near Yitzhar, Nahla Mahmoud said settlers enter almost every week. Her home is the closest to the settlement and has been repeatedly attacked by settlers.

The worst incident was last month after a 16-year-old Palestinian from the village entered Yitzhar and burned a house there. According to the Israeli army and the settlers, he then stabbed a 9-year-old boy several times, slightly wounding him, and fled back to the village. He was killed the following week by Israeli troops when he tried to approach the village again.

Just hours after the stabbing attack in Yitzhar, a group of settlers attacked Mahmoud's home, cutting the water pipes, smashing the solar panels, uprooting trees and painting black Jewish stars on the side of her house, she said. She caught it all on videotape, with a camera supplied by B'Tselem.

Israeli Prime Minister Ehud Olmert harshly criticized the attack on the Palestinian village, calling it a "pogrom."

Mahmoud said the settlers are trying to make her life intolerable and force her to leave her home.

"They want this land to become part of the settlement," she said. "They don't believe this is our land and our homes. We have this land registered with the government from the time of our grandfathers. I have no intention of leaving because I have nowhere else to go."

The clashes between settlers and Palestinians have spilled over into tensions between settlers and the army.

Shamni said that in the past few weeks, settlers set a dog on an Israeli reserve commander and broke the arm of a deputy battalion commander. The tires of cars belonging to reserve soldiers were slashed. And in the southern town of Hebron, settlers attacked an officer for trying to arrest Jewish children who had thrown stones at Palestinians.

Yitzhar, home to 160 families and isolated on a hilltop, has long been known as a bastion of radicalism. Residents say it is their presence that prevents an Israeli withdrawal from the area.

Ben Yakov, 31, said he has refused to do mandatory reserve duty for the past three years, since Israel's 2005 withdrawal from Gaza. During the pullback, Israel dismantled 21 settlements in Gaza and soldiers forcibly removed many of the settlers from their homes. The Gaza pullback had an especially profound effect on young settlers, who had grown up with a belief that the Israeli army was fulfilling a holy mission of defending Jews who wanted to settle in all parts of the land of Israel.

Ben Yakov's sister-in-law, Tzippi Feld, said the Gaza withdrawal shook her faith in the army. Feld spent months demonstrating against the planned pullback and served a month in jail for trying to block traffic at the entrance to Jerusalem.

"We used to be so Zionist and so proud of our state and our army," the 26-year-old dance teacher said. "But after the pullback from Gaza, it all collapsed. I'm so upset with the government. I feel like they're abandoning so many of us."

Compounding settlers' frustration over the Gaza pullback is alarm over recent statements by Olmert in which he suggested that Israel needs to withdraw from nearly all the West Bank in order to make peace with the Palestinians. Settlements like Yitzhar, which are east of the barrier Israel is building in and around the West Bank, would be the first to be left behind.

The growing extremism among settlers gained prominence last month after an attack on Zeev Sternhell, a professor and prominent critic of the settlement movement. Sternhell was slightly wounded when a pipe bomb went off as he opened the door to his apartment at 1 a.m. Fliers were found nearby offering a large reward to anyone who kills members of Peace Now, a dovish group.

Olmert, who resigned the prime ministership last month but remains head of a caretaker government, harshly condemned that attack.

"An evil wind of malice, of hatred, of extremism, of lawlessness is blowing through certain sectors of the Israeli public and threatens Israeli democracy," he told his cabinet.

The bombing raised fears of growing divisions within Israeli society, and brought back memories of the 1995 assassination of Yitzhak Rabin by an extremist Jew, Yigal Amir, who wanted to stop the peace process with the Palestinians.

"The sense that it is getting out of hand was stronger after the attack on Sternhell," said Gershom Goremberg, author of "The Accidental Empire," a history of the settlement movement. "Internal fratricide is much more frightening than violence which takes place across the line of national conflict. I think it's a mistake if you let a culture of vigilantism flourish against the Palestinians. It's only a matter of time until it affects Jews as well."

Even some veteran settler leaders are concerned about increasing radicalism. Yisrael Medad, a settler spokesman, said young settlers are angry with settlement leaders for not doing enough to stop the Gaza withdrawal. Many settlers, he said, are suspicious that the government is planning a much larger withdrawal from the West Bank, and they are determined to prevent that.

"There are radical elements who are reacting less responsibly than we would like to see them do," he said. "There are a few hotheads running off and doing things of a criminal and violent nature, and we are trying to deal with it educationally."