Security sources said Jewish settlers had been evacuated from Atzmona, Slav and Katif, the last enclaves remaining in the Gush Katif bloc.
Police were still scouring the area for rightist youths who had slipped in to reinforce resistance to the evacuations.
The army had no immediate comment on the situation in Gush Katif, but said its forces had evacuated the northern Gaza settlement of Elei Sinai.
With Gush Katif emptied of residents, the sole remaining settlement in occupied Gaza is Netzarim, which is scheduled to be evacuated on Monday, allowing the entire Gaza evacuation to be compressed into one week.
Before the evacuation began, Israeli leaders said it might take three weeks to remove all the settlers from Gaza, taking into account attacks from Palestinians or extremist Israelis.
The evacuation has proceeded with little violence, but an Israeli soldier was wounded when Palestinians opened fire on an army post in southern Gaza on Sunday.
"An Israeli soldier was wounded in his hand by Palestinian fire
Bulldozers have moved in to
demolish Jewish settlements
on an Israeli post guarding Neve Dekalim," an army spokeswoman said.
The soldier, who was lightly injured, was taken to hospital, she added.
Neve Dekalim, once the largest Jewish community in Gaza, was
evacuated of all residents last week.
Thousands of Palestinian security forces have been deployed around the perimeter of the settlements to guard against attacks on Israeli troops and settlers during the pullout.
Officials hope all 21 Gaza settlements will be empty by Tuesday.
Israel's cabinet gave final approval on Sunday to the evacuation of the last seven of 25 Gaza and West Bank settlements marked for dismantling.
Meanwhile in the West Bank, extremists exchanged blows with soldiers and slashed tyres of army jeeps near Sanur, one of the enclaves to be dismantled later this week.
In comments at the start of a cabinet meeting on Sunday, Prime Minister Ariel Sharon called acts of violent resistance to the pullout "hooliganism" and said Jewish settler leaders - once his friends and allies - were exploiting the suffering of their followers to push a political agenda.
Bulldozers at work
The last Gaza colony, Netzarim,
is to be evacuated on Monday
Earlier on Sunday, bulldozers smashed through the gated front entrance of Katif, where settlers had set fire to piles of tyres and rubbish, before several hundred troops and police surged in to begin evicting residents.
In Atzmona, more than a thousand unarmed troops and police forces barged through the entrance, greeted by chants of "Jews do not expel Jews" where about 60 families and 200 right-wing activists are still holed up.
In the evacuated Ganei Tal, workers were drilling and hammering away to dismantle the interior of the synagogue as evicted settlers were allowed back in to pack their belongings.
Evacuation of the four West Bank enclaves - out of 120 - is expected later in the week, after completion of the Gaza operation.
The Israeli cabinet formally
approved the final pullout phase
Two of the four, Ganim and Kadim next to the West Bank town of Jenin, are empty, but security officials estimate that more than 2000 extremists have moved into the other two, where a few a dozen families were living when the pullout plan was announced almost two years ago.
The extra hands have shown potential for igniting violence during the evacuation, and a security official acknowledged that a scenario of holdouts opening fire on troops was possible.
Preparing to take control of the settlement areas in the most significant change in the Middle East map in decades, Palestinian President Mahmoud Abbas signed a decree on Saturday appropriating Jewish settlement land for public use once Israel's evacuation is complete.
Abbas' proclamation seizing control of the evacuated Gaza land was meant to assert the authority of the Palestinian government in an area still largely dominated by political regional commanders, and where corruption among officials is deeply ingrained.
Many Palestinians feared prime land could end up in the hands of senior officials of the ruling Fatah organisation.
The 21 settlements, with 8500 residents, and several military installations controlled about 20% of the land in the narrow coastal strip that also is home to 1.3 million Palestinians.
Mahmoud Abbas signed a decree
expropriating occupied land
About 9% of the land expropriated by Israel is claimed by private Palestinian owners, who will have an opportunity to reclaim their property, while the rest had been in the public domain.
Abbas has warned his people that the world will regard developments in Gaza as a test of whether the Palestinians are ready for independence.
Earlier, Abbas met US State Department Assistant Secretary David Welch and expressed the need for continued US concern for the future of the Middle East after the pullout.
Welch's surprise visit was the first by a US envoy to Gaza since a US diplomatic convoy was attacked two years ago in the occupied strip.
Sharon has insisted that Abbas pacify Gaza and disarm resistance groups before he agrees to return to talks about the road map peace plan, introduced more than two years ago by US President Bush, but quickly stalemated.
As Abbas issued his decree, dozens of masked fighters from the Hamas movement briefly took over the central square of Gaza City in a show of defiance against the president, and made clear the resistance had no intention of disarming.
Up to 9% of Gaza land is claimed
by private Palestinian owners
"We will keep all our weapons, and our military equipment, and we will develop it further, God willing. Our battle with the enemy is long and will continue," said a spokesman known only as Abu Obaideh.
Abbas also announced that 25 January will be the date for Palestinian parliamentary elections, postponed from July.
Hamas is expected to do well in the voting, fielding candidates for the first time.