NEVE DEKALIM, Gaza Strip – Israeli police cut through the main gate of the Gaza Strip”s largest settlement Tuesday, seizing control of a key flashpoint and igniting clashes with settlers who have resisted orders to leave the community under Israel”s Gaza withdrawal plan.

Security forces arrested at least nine people who tried to block trucks from entering the Neve Dekalim settlement. Hundreds of pullout opponents pushed troops and police trying to clear a way to help settlers leave before a midnight deadline for voluntary evacuation.

The clash was the roughest confrontation between pullout opponents and security forces since Israel”s Gaza pullout got underway on Monday.

The show of force by security forces stepped up pressure on pullout opponents, including hundreds of extremists who have sneaked into the area, to allow the withdrawal to proceed peacefully.

&#34If there are no problems, then we won”t have anything to do here. If there are disruptions, then we will impose law and order,&#34 Maj. Gen. Dan Harel, the army”s commander for the Gaza region, told Israel TV.

With the deadline approaching, officials said they were hopeful many residents would leave Tuesday. Anyone who remains after the deadline faces forcible eviction and the loss of up to one-third of government compensation — a sum that could total tens of thousands of dollars.

Israeli officials said one-third to one-half of Gaza”s 8,500 settlers had already left. Police said about 120 moving trucks were expected to head into Neve Dekalim later in the day. At midmorning a large convoy of trucks was seen entering Gaza.

Israel Radio said three Gaza settlements were totally empty Tuesday, and five others were quickly thinning out. But residents in a handful of communities appeared to be digging in for a fight.

In a three-week operation, Israel plans to remove all 21 settlements from Gaza and four from the West Bank. It is the first time Israel has removed veteran settlements from either area, which are claimed by the Palestinians for a future, independent state.

Israeli forces began the operation on Monday, attempting to hand out eviction orders to residents of all settlements slated for evacuation. While there were no violent clashes, many settlers refused to cooperate, jeering troops, tearfully confronting them or destroying the evacuation notices.

In Neve Dekalim, hundreds of protesters, many of them teenagers wearing orange, the symbolic color of resistance, barred forces from entering Monday. Young activists also impeded moving trucks from entering and exiting the settlement.

But early Tuesday, there were few protesters at the gates of Neve Dekalim, and police entered the settlement without incident. Officers used an electric saw to cut through the main gate.

&#34Now the police can decide when it opens and when it closes,&#34 said police spokesman Avi Zelba. &#34Now people who want to move can go out freely.&#34

At midmorning, however, a large crowd of youths gathered near the gate in a renewed attempt to prevent moving trucks from entering.

Much of the opposition appears to be coming not from residents, but from extremists from outside the area. Officials estimate some 5,000 pullout opponents have sneaked into Gaza in recent weeks to resist. Zelba said about 500 people illegally in Gaza were arrested overnight, and dozens were arrested trying to infiltrate from Israel.

Harel, the Gaza commander, said young activists had blocked residents from leaving Neve Dekalim on Monday, and that the army was determined not to let that happen again.

&#34What happened yesterday, there was a violation of the law,&#34 he said. &#34We will let people leave freely.&#34

Yehuda Glick, a West Bank settler who infiltrated Neve Dekalim, said he and other activists had no plans to surrender. &#34Everybody will be given an assignment. There will be those who will be given the assignment to be troublemakers, and there will also be those who will make sure the troublemakers don”t go too far,&#34 he said. &#34I hope there won”t be any wounded soldiers or policemen.&#34

In the isolated Gaza settlement of Morag in southern Gaza, residents appeared to be heeding calls to leave. About one-third of the settlement”s 220 residents had left by early Tuesday, and many others were packing up. Many houses were empty with even doors and windows taken by their owners.

However, the army said an estimated 300 hardline outsiders remained holed up in the settlement.

Morag resident Gazi Itzrak said he was sad to leave, but thinks Sharon”s reasons for leaving Gaza will help Israeli security. &#34We live here in the heart of Arab land. I believe he thought, ”On second thought, we should back out now and leave them in peace here.”&#34

In central Gaza, the hardline settlement of Netzarim showed no signs of preparing to leave. Residents spent the night in a communal celebration, singing and dancing and waving orange flags.

&#34The party was the focus of many energies that exploded out. … Here it explodes with happiness,&#34 said resident Eyal Vered. He added residents would not use weapons against soldiers.

In a televised speech Monday evening, Sharon praised Gaza”s settlers as &#34pioneers,&#34 but insisted that it is time for Israel to leave the area after 38 years of occupation.

&#34We cannot hold Gaza for good,&#34 he said. &#34More that a million Palestinians live there, doubling their numbers every generation.&#34

Sharon also urged Palestinian leaders to control extremists. &#34To an outstretched hand of peace, we will respond with an olive branch, but fire will be met by fire more intense than ever,&#34 he said.

Palestinians have praised the withdrawal but insist it must be the first step toward a peace agreement giving them an independent state that also includes the entire West Bank and east Jerusalem.

Sharon has explained that by leaving Gaza and the northern West Bank, Israel can solidify its grip on parts of the West Bank where most of its 240,000 settlers live.

Palestinian militants, meanwhile, have been trying to claim that their relentless attacks in Gaza over the past five years drove the Israelis out.

In the southern town of Rafah, about 1,000 Islamic Jihad activists rallied Monday, declaring that the Israeli withdrawal is a &#34victory for the resistance.&#34

Hamas planned a similar demonstration Tuesday in Khan Younis, next to the Gush Katif bloc of settlements. Hamas spokesman Sami Abu Zuhri said the group would not attack.