A right-wing activist set herself ablaze Wednesday during an anti-pullout protest in the Negev town of Netivot.

She was seriously wounded, suffering from burns on 60 percent of her body. She was taken to Soroka Medical Center in Be'er Sheva for treatment.

Police said Wednesday morning that in the last 24 hours they had arrested 498 pullout opponents, of whom 451 were released.

Also Wednesday, 48 people, some of them armed, were arrested on their way to the northern West Bank settlement of Homesh.

In recent days, police and Shin Bet security service officials have been hard at work trying to identify and locate hard-core elements among the infiltrators, including extremists who might use violence against the security forces or carry out a terror attack against Palestinian targets.

In the wake of AWOL soldier Eden Natan Zada's terror attack in Shfaram on August 4, security forces have intensified their intelligence efforts with regard to the so-called hilltop youth, particularly the hard-core group from the West Bank settlement of Kfar Tapuah, where Natan Zada had lived in recent months.

A number of right-wing extremists, including hilltop youth leaders, have been questioned recently, but security sources say the police and Shin Bet have not garnered any concrete information regarding plans by radical elements to carry out terror-like attacks on the evacuating forces or use arms to oppose the pullout.

The most radical elements expected to resist the evacuating forces in Gush Katif over the coming days will presumably be individuals who infiltrated the Gaza Strip following its closure to non-residents on July 13. Recent days have seen increased tension between settler leaders and the outside elements, with the former appearing to have lost control over the extremists.

"Those lunatics should be thrown out of here," said Yesha Council of settlements member Shaul Goldstein of the youths who in recent demonstrations in Neveh Dekalim vandalized military vehicles, threw objects and paint at soldiers and police, and prevented shipping containers from being brought into the settlement.

Other Gush Katif residents have accused the visitors of compromising their struggle against the evacuation.

The largest number of infiltrators is in Neveh Dekalim, and some of the Gush Katif youth have joined up with the more radical groups that are planning to put up a fight when the evacuation forces arrive.

Other settlements, such as Netzarim, have made efforts to get rid of such groups; while in Kfar Darom, the 1,300-1,500 anti-disengagement activists who have arrived in the settlement in recent weeks have been made well aware in recent days of the boundaries of the struggle and its non-violent nature.

One of the biggest issues facing security forces is how so many non-residents were able to enter Gush Katif and the northern West Bank settlements and how the people illegally present in the communities will conduct themselves during the evacuation.

Police sources refused Tuesday to provide any official figures regarding infiltrators in the settlements slated for evacuation, saying that there had been a mass exodus from the area in recent days and that it was impossible to say with any certainty how many still remained there. The sources said, however, that up to 5,000 infiltrators could still be in the settlements.