Security forces stormed two synagogues and an old British fortress in the northern West Bank settlement of Sa-Nur on Tuesday morning, as part of the operation to clear the last two enclaves slated for evacuation under Prime Minister Ariel Sharon's disengagement plan.

By midday, 246 Israeli civilians had been evacuated from 19 buildings in Sa-Nur, the military said.

Despite the removal of protesters from inside the stone citadel, some remained on the barbed wire-adorned roof of the building, among them National Union lawmaker Aryeh Eldad, Yesha Council official Pinchas Wallerstein and Rabbi Lior Dov.

Around 2 P.M., police forces were entering a container to be prepared to be lifted onto the roof of a citadel and remove protesters, many of whom are armed with iron rods and shields.

The military had decided in advance that if protesters moved into the fortress, the police special missions unit would be charged with overcoming and evacuating those inside.

Soldiers, carrying shields and wearing helmets, had earlier used circular saws to cut open the iron door of the ground floor of the fort, where the fiercest opposition had been expected, and began removing the protesters inside.

One boy, aged about 10 years, kicked and shouted as he was carried off by four policemen.

Most of the families who lived in the settlement have departed, leaving only extremist infiltrators determined to disrupt the disengagement.

"There were 60 families in Sa-Nur but [few] are left now. What we're dealing with here is a huge number of infiltrators who make this much more a fight over ideology," said army spokesman Jonathan Schroeder.

"Our current estimate is that there are 1,000 protesters here, mostly out of sight, holed up in houses," Israel Police Commissioner Moshe Karadi told reporters.

At the Chabad synagogue, troops from the Home Front Command and Border Police gathered at the door, which protesters had welded shut from inside. After a brief exchange, the troops moved to slice open the doors.

Inside the synagogue, around 20 ultra-Orthodox young men were sitting on the floor, while one man walked around, hugging a Torah scroll. A police commander was surrounded by weeping and chanting worshippers as he made one last appeal that they leave voluntarily.

The protesters were eventually taken out of the synagogue, some being forcibly removed by troops.

Police also moved into a larger house of worship, clearing out the dozens barricaded inside. The windows of the synagogue had been blocked by coils of barbed wire.

The evacuation operation began early Tuesday morning, when thousands of troops removed the gates of Sa-Nur and poured into the settlement and the neighboring Homesh.

About 2,000 extremists with an arsenal of weapons are thought to be in the two settlements, determined to foil the last stage of the disengagement.

Within hours of entering the settlement, troops had cleared away the tents that had housed protesters from outside Sa-Nur, and the first families had been bused out.

Some settlers harangued soldiers. One confronted a woman officer, held up a portrait and said: "Here's my son, who was murdered by Palestinians, and now you want to expel his father."

The residents of one barricaded house were forcibly evacuated after troops removed the windows.

Electricity to the settlement was cut off Tuesday morning, due to fears that a blaze from burning tires in Sa-Nur would reach the power lines overhead.

Lines of police and soldiers, some in anti-riot gear, advanced through Sa-Nur, expected to be the main focus of anti-disengagement resistance.

Approaching troops were greeted by young women and girls praying in the streets wearing orange or yellow stars, invoking the treatment of the Jews at the hands of the Nazis.

The settlement is now home to a few remaining residents, along with a crowd of "reinforcements," including many activists from the extreme-right Kach movement and members of the "hilltop youth" - known for their extremism and rejection of the government's authority.

The security forces are acting on the assumption that some of these pullout opponents are carrying firearms, but say there is only a slight chance that any shots will be fired.

MK Aryeh Eldad (National Union), speaking to Channel 10 television from a barricaded roof at the heart of the settlement, said Tuesday morning that, to the best of his knowledge, there were no weapons left in Sa-Nur.

"We don't want to give police and army troops any excuses to use violence," he said.

Before dawn Tuesday, security forces arrested Rabbi Shlomo Eliyahu of Safed and one of his students, who intended to enter Sa-Nur, Israel Radio reported.

The two claimed to have permits to enter the settlement, but the troops refused to let them through. Rabbi Eliyahu has made several extreme comments in the past, including calling on soldiers and police to refuse orders related to the disengagement plan.

"Our problem is with these 'reinforcements,' two or three of whom arrived Monday night, who will not listen to the rabbis' instructions," GOC Central Command Major General Yair Naveh said Tuesday.

"It may well be that here we will find our next 'lone terrorist.' This is what is worrying us, and, unfortunately, it is out of our control. We are dealing with youths who, as they see it, just want to protect the Holy Land. Sometimes, they cross the lines of what is legitimate."

Senior officers believe that opposition will be much fiercer than the scenes at Kfar Darom last week.

Police Commissioner Moshe Karadi said Monday evening police were prepared for any possible scenario during the evacuation of the two settlements.

Sa-Nur secretary Yossi Dagan said reports about the protesters' plans to use violence could be chalked up to attempts by security forces to manipulate the public, and said the right-wing activists would resist the evacuation in a reasonable manner.

Five youths, as well as a couple and their ten children, left Sa-Nur voluntarily Monday. They asked to leave the settlement before the outbreak of possible violent resistance during the evacuation of the settlement, and police escorted them to a bus that transported them out.

The residents of Ganim and Kadim, the two other settlements in the northern West Bank to be evacuated, have already left voluntarily. Demolition of houses in Ganim began Tuesday morning.