On the first day of the Israeli pullout from the Gaza Strip (search), some Jewish settlers weren't going quietly.

Many had evacuated their homes ahead of the official start of the pullout just after midnight Monday. But those who refused locked the gates to their settlements and clasped hands, forming human chains, to block soldiers from delivering dreaded eviction notices.

Israeli Prime Minister Ariel Sharon (search) said in a televised speech that the Gaza pullout was a painful step, both for the nation and for himself, but that it was essential for Israel's future.

A grim-looking Sharon said it is now up to the Palestinians to clamp down on militants and stop violence. "To an outstretched hand we will respond with an olive branch," he said.

The Israelis plan to withdraw from most of Gaza and four small West Bank settlements over a three-week period in an effort to advance the peace process and pave the way for the future formation of a Palestinian state. Israel has occupied both territories for 38 years.

"It's a painful and difficult day, but it's a historic day," Israel's Defense Minister Shaul Mofaz (search) said.

Police and soldiers waited patiently in the sweltering sun and avoided confrontation at the behest of their commanders. In one scene, a sobbing settler pleaded with a brigadier general not to evict him before the two men embraced.

Israel plans to remove all 21 Jewish settlements from Gaza, plus the four West Bank outposts. The withdrawal marks the first time Israel will dismantle settlements in areas captured in the 1967 Mideast War and claimed by the Palestinians for their future state.

While Sharon says the pullout will improve Israel's security, Jewish settlers fiercely oppose the plan and have promised stiff, but nonviolent, resistance.

Israeli Army Chief Dan Halutz told FOX News that so far, everything was going as planned.

He said the most trouble would come "the day after disengagement. Then we will have to face the same problems we face today in Israeli society."

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

In Gaza City, the Islamic militant group Hamas (search) hung banners proclaiming the pullout is a result of attacks by militants on Israelis.

"The blood of martyrs has led to liberation," one banner said.

Also Monday, Palestinian officials said Palestinian leader Mahmoud Abbas (search) has scheduled long-delayed legislative elections for Jan. 21. Saeb Erekat (search), a government spokesman, said Abbas would issue a formal decree on Tuesday or Wednesday.

The elections had initially been set for July 17 but were delayed. Abbas cited technical reasons, but Hamas has accused him of seeking additional time to shore up support for his embattled Fatah party.

Thousands of Israeli troops marched into Gaza's settlements, delivering eviction notices in six settlements, but encountering 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 government compensation.

Resistance was stiff in Gush Katif. Hundreds of settlers blocked the gates of Neve Dekalim (search), Gaza's largest settlement, to prevent the forces from entering.

Dozens of observant Jewish men, wearing white prayer shawls, held morning prayers at the gate, appealing for divine intervention to block the withdrawal. A crowd of youths wearing orange, the color of defiance, sat on the streets and screamed at the soldiers.

"You're a partner to a crime," screamed one protester.

Troops moved into the community through a second entrance, only to be blocked by crowds who burned tires, formed human chains and scuffled with troops. When some 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 one standoff, protesters in Neve Dekalim allowed a large convoy of moving trucks to enter the main gate, and army officials said at least 200 settler families 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 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 hastily escorted away by police after he was confronted by angry settlers.

Although many of Gaza's 8,500 Israeli residents have already left, the army estimates that thousands remain, including some 5,000 hardliners who have infiltrated Gaza to resist the pullout. Much of Monday's resistance appeared to come from the outsiders.

At the tiny, 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.

"I am not your enemy. I served as an officer under you," the man told Brig. Gen. Erez Zuckerman, the commander of the army unit waiting at the gate.

Zuckerman listened and wiped sweat off his brow, then hugged the young man.

"We love you, you are part of us," he told the settlers.

In nearby Netzer Hazani (search), Alan Sherr, a Philadelphia native who moved to Gaza in 1979, hung an American flag upside-down outside his home. Sherr, wearing a Philadelphia Eagles cap, said he was protesting President Bush's support for the withdrawal.

"I'm feeling every negative emotion in the English dictionary," he said. "I have no more happiness and no more pride. They have taken it all away."

Resistance was much more subdued in the settlements of Nissanit, Elei Sinai and Dugit, secular communities in northern Gaza that were virtually emptied out.

In Nissanit, four soldiers came to the home of Yitzhak and Avigail Dadon, a couple in their 70s who said they would leave before the forcible removal begins. Yitzhak Dadon said that earlier in the morning, he lowered an Israeli flag that had been fluttering from his roof. Avigail Dadon cried, and a female soldier stood up to hug her.

Two residents entered an abandoned home, took out a hammer and smashed the remaining mirrors, doors and windows. Some homes were covered in graffiti, including one that read "Sharon is a Nazi."

Soldiers also helped settlers pack. In one Nissanit home, troops removed a large sundeck next to a backyard swimming pool, pulling out planks and stacking them up in a pile.

In Elei Sinai, one man put lawn chairs and a TV set on the roof, where he said he would remain with his young daughter until he is removed.

"Elei Sinai won't fall," read a large sign outside his home.

Soldiers were also giving eviction notices in four West Bank settlements slated for evacuation. They chose not to enter two of the communities, Sanur and Homesh, where hard-line extremists have holed up. The army instead planned to hand the orders to community leaders.

Israel's Cabinet met Monday and gave final approval for the removal of additional Gaza settlements in what was seen as a formality. The plan was already approved by the government and parliament during a bruising yearlong political battle.

With some 50,000 security forces involved, the "disengagement" from Gaza is the nation's largest-ever noncombat operation.

Abbas said the Gaza pullout is a "historical moment," but that Israel must also hand over the West Bank and east Jerusalem.

"If they want peace, they must allow Palestinians to achieve their rights," the Palestinian leader told the BBC World Service.

The Palestinians hope the pullout from Gaza will lead to the resumption of peace talks, and ultimately full independence in areas captured by Israel in the 1967 Mideast War.

But they fear the withdrawal is a ploy by Sharon to get rid of areas he doesn't consider crucial to Israel while consolidating control of parts of the West Bank, where the vast majority of the 240,000 Jewish settlers live.

FOX News' Jennifer Griffin and The Associated Press contributed to this report.