Israeli troops fired in the air Monday to keep back hundreds of Palestinians, including a few dozen masked gunmen, who marched toward southern Gaza's Gush Katif group of settlements in celebration of the impending withdrawal. The crowd burned a cardboard model of an Israeli settlement, complete with an army watchtower.

With some 50,000 soldiers and police involved, the withdrawal was Israel's largest-ever noncombat military operation.

Israeli troops who fanned out across the Gaza Strip delivered eviction notices in six settlements, but met protests in others. The notices gave settlers until midnight Tuesday to leave. If they ignore the deadline, they will be removed by force and could lose up to a third of the compensation being offered by the government for giving up their homes.

Although many of Gaza's 8,500 settlers already left, the army estimated thousands remained, bolstered by some 5,000 hard-liners who came to help residents resist the pullout.

Settlers were defiant at Gush Katif. Hundreds blocked the gates of Neve Dekalim, Gaza's largest settlement, to prevent troops from entering.

Dozens of men, wearing white prayer shawls, held morning prayers at the gate, appealing for divine intervention to block the withdrawal. Youths wearing orange, the color of defiance, sat on the streets and yelled at soldiers. "You're a partner to a crime," one screamed.

Troops moved into the community through a second entrance, only to be blocked by crowds who burned tires, formed human chains and scuffled with soldiers. When a small group of soldiers managed to enter, settlers took the eviction notices and burned them. One policeman was covered in green paint thrown by protesters.

Despite the standoff, there were signs that residents would leave before the deadline. After negotiations with police, protesters in Neve Dekalim allowed a large convoy of moving trucks to enter through the main gate, though young activists sporadically blocked the vehicles. Army officials said at least 200 settler families throughout Gaza had asked for assistance in moving their belongings.

"This morning, the people stood up to the police and it was a victory. Now the (shipping) containers are coming in. It is heartbreaking and negative," said Yosef Meron, 68, of Neve Dekalim.

Military commanders listened to the settlers' appeals, but said they would not be deterred.

Maj. Gen. Dan Harel, Israel's commander over the Gaza region, said the operation was going as anticipated. "Our estimation is that by tomorrow night most of the residents will agree to leave," he said.

Harel attempted to talk to residents of Neve Dekalim, but was whisked away by police after he was confronted by angry settlers.

At the isolated Morag settlement, hundreds of people blocked troops at the gate. One man, identified by Israeli media as Liron Zeidan, burst into tears as he pleaded with officers not to remove him from his home.