NISSANIT, Gaza Strip -- Israeli bulldozers tore down red-roofed villas and scattered debris across green lawns yesterday, virtually erasing Jewish settlements within a few hours and delivering a graphic message that Israelis will no longer live in the Gaza Strip.
The demolitions were conducted as the army announced that 20 of the 21 Jewish settlements in Gaza had been emptied by yesterday evening.
In the West Bank, Israeli security forces skirmished with some of the thousands of ultranationalists defending two northern settlements amid fears that they may use weapons when troops begin evicting residents, most likely tomorrow.
Dozens of settlers swarmed troops setting up a staging area near the Sanur settlement in the West Bank, slashing tires of military vehicles and exchanging blows with soldiers in a prelude to what could be the most difficult mission of Prime Minister Ariel Sharon's ''disengagement" plan.
Sharon denounced the violent resisters during a Cabinet meeting that approved the final phase of the pullout. He also accused settler leaders of exploiting the anguish of their people to push their political agenda, delivering his harshest criticism of his onetime friends and allies.
''The things they did were acts of hooliganism and in my opinion, borderline criminal," Sharon said. ''This doesn't just reflect on them but on those who sent them and incited them and directed them."
Moving more swiftly than planned, officials hope to complete the removal of settlers from Gaza and the northern corner of the West Bank by the end of the week in an operation that a US envoy predicted would reinvigorate Mideast peace efforts.
''The United States views the Israeli disengagement from Gaza as an important opportunity . . . to take further steps forward toward a better future for Israelis and Palestinians," said Assistant Secretary of State David Welch, the first senior US official to visit the coastal strip since Palestinian militants killed three Americans in a diplomatic convoy two years ago.
Troops in overwhelming numbers brushed past barricades and steel gates yesterday to enter four Gaza settlements and escort teary residents to buses. Settlers bid farewell to communities they built over decades, repeating anguishing scenes that have gripped Israelis almost daily for a week.
The final Gaza evacuation was to come today at Netzarim, a community of 400 just south of Gaza City that was one of the first Israeli outposts built in the coastal strip.
Huge D9 bulldozers, many driven by Israeli Arabs, tore down homes in Nissanit, Dugit, Peat Sadeh, and Ganei Tal. They reduced entire villages to garbage dumps in less than a day. In Ganei Tal, 40 houses came down in an hour.
Victor Bargil, a senior Defense Ministry official, said he expected all Gaza houses to be demolished within two weeks -- half the time predicted last week by Defense Minister Shaul Mofaz. The army also must dismantle its installations before the Palestinian Authority takes control, probably within the next month.
In the West Bank, dozens of Jewish extremists scuffled with Israeli soldiers outside Sanur, an extremist stronghold marked for evacuation in the next few days.
Settlers climbed on two armored bulldozers brought in to clear land in preparation for the pullout. About a dozen soldiers tried to push back the protesters.
Witnesses said settlers hit soldiers, who struck back. The settlers also slashed the tires of an army jeep and attacked a television cameraman, the witnesses said.
About 200 police arrived and dispersed the settlers. Ten policemen and soldiers suffered light injuries in the melee, and two people were arrested.
Hundreds of soldiers and police were being flown by helicopters from the Re'im camp in the south to the West Bank for the evacuation of Sanur and nearby Homesh. Residents of two other small West Bank settlements slated for removal already left their homes voluntarily.
Military officials cited intelligence reports saying some of the estimated 2,000 extremists who moved into Sanur and Homesh had weapons and might be ready to use them. The army said it was considering using armed troops for the evacuations there, unlike in Gaza where unarmed security forces carried out settlers.
Later yesterday, eight masked Jewish extremists attacked an army tractor in the northern West Bank near Kedumim, a settlement not slated for dismantlement. The attackers slashed the tractor's tires, then set it on fire while a soldier was still in the vehicle, Israeli media reported. The soldier got out and pointed a gun at the attackers, who escaped.
In Gaza, the army said a soldier at an army base was slightly wounded by gunfire, the first Israeli injury from Palestinian fire since the withdrawal began. Palestinian militants generally have held their fire during the pullout, but have occasionally fired rockets, mortar shells, or automatic weapons.