Six Jewish men were arrested in Jerusalem yesterday on suspicion of torching a mosque in the capital Tuesday night and spraying its walls with anti-Islamic graffiti, including "Mohammed is a pig."

The suspects belong to a group of right-wing extremists who are under a restraining order issued by the Israel Defense Forces about six months ago that requires them to stay away from the West Bank settlement of Yitzhar.

The arrests were carried out amid violent clashes between dozens of extremists and policemen, in which the rioters slashed the tires and smashed the windows of several police cars.

Since being ordered away from Yitzhar for fear they would instigate violent clashes, the suspects have been living together in an apartment in Jerusalem's Kiryat Moshe neighborhood, near the Mercaz Harav yeshiva.

As soon as the police arrived at the suspects' apartment yesterday, dozens of young men in skullcaps gathered outside and clashed with the officers in a bid to prevent the arrests.

Eyewitnesses said policemen hurled rioters who fought with them out the first-floor window.

In the apartment, officers confiscated fake weapons as well as documents that may be used as evidence.

One of the neighbors, Daniel, told Haaretz that "police are chasing 20-year-olds around instead of looking for real criminals." He insisted that "the young men weren't violent at all."

"These are people who were legally expelled and moved here," he added. "They have to live somewhere. This is the first time I have ever seen police officers acting without a warrant or documentation."

The arrests followed Tuesday night's torching of a historic mosque in what was apparently a "price-tag" attack - a term right-wing extremists coined for attacks on Palestinians or soldiers meant to "exact a price" for house demolitions in the settlements.

At about 3 A.M., the city's fire department received a call about smoke coming out of a mosque on Strauss Street, near the city center. The street has two adjacent mosques, both of which have been deserted since the establishment of the state. In recent years, the municipality has used them to store gardening tools.

The firemen found numerous graffiti sprayed on the walls, including "price tag," "a good Arab is a dead Arab," "Kahane lives" (a reference to the late Rabbi Meir Kahane ) and several Stars of David.

A few hours after putting out the fire, the city sent workers to clean the graffiti off the mosque walls. One city worker said this was the third time in five years that the mosques had been set on fire.

The recent wave of violence by right-wing extremists has sparked denunciations from the entire political spectrum, and the expressions of outrage continued yesterday.

Defense Minister Ehud Barak said Israel should consider classifying the so-called hilltop youth - a group of young settlers affiliated with the extreme right - as a terrorist organization.

"From the way they behave, there's no question that this is terrorist behavior," Barak told Army Radio. "Is it an organization, or is it just a collection of individuals? How can we define them collectively?"

Barak said it is vital to nab the guilty parties quickly so that "the normative settler community in the West Bank - the majority of the population - won't be suspected."

In one unusually harsh comment, former Defense Minister Benjamin Ben-Eliezer said IDF soldiers should have shot the right-wing rioters who broke into an army base in the West Bank Monday night.

Opposition leader MK Tzipi Livni (Kadima) said "the government must act right now to stop all those involved ... and stop allowing the Knesset to pass radical legislation and the rabbis to rant and rave."

Labor Party chairwoman MK Shelly Yachimovich said "the torching of the mosque could ignite a dangerous regional conflagration, so the police and the security services must concentrate on catching the rioters and bringing them to trial."

Intelligence Minister Dan Meridor (Likud) slammed "the violent, savage attacks," saying the people behind them are threatening and defying the entire state.

"The settlements have become incubators for criminals," said MK Talab al-Sana (United Arab List-Ta'al ), who visited the mosque together with MKs Ahmed Tibi (United Arab List-Ta'al ) and Mohammed Barakeh (Hadash ).

In a related story, on Monday evening hundreds of extremist right-wing activists, some of them with masks on, rioted outside Ramat Gilad. They hurled stones at Palestinian vehicles, attacked the female soldiers guarding the outpost and broke into the nearby Ephraim Brigade headquarters near the Kedumim settlement.

IDF sources told Haaretz a military force was dispatched to extract the women safely from their post after rioters insulted them and called them "Nazis."

Senior IDF officers yesterday slammed the settlers' leadership and rabbis for their conduct in view of the riots and attacks on soldiers. They said the settlers' council heads and many rabbis are afraid of confronting the violent extremists and only feebly denounce their attacks on soldiers and Palestinians.

IDF sources said yesterday there was no intention of changing the rules of engagement in the West Bank, as the existing rules are adequate to deal with the settlers' disorders.