KFAR MAIMON, Israel -- Israeli police backed by officers on horseback sealed off an encampment filled with thousands of Jewish settlers and their supporters Tuesday, trading punches and dragging off protesters in the biggest confrontation yet over Israel's withdrawal from Gaza.
The government has vowed to stop protesters from marching to Gaza Strip settlements marked for evacuation in August, fearing that more Israeli hard-liners at the sites would further complicate the contentious pullout.
Demonstrators said they would stay in their makeshift protest camp in the farming community of Kfar Maimon and try to march again Wednesday -- and the next day and the next -- setting the stage for more confrontations.
"As long as this terrible decision stands (to withdraw from Gaza), there will be a constant presence to prevent this," settler leader Pinchas Wallerstein told Army Radio.
The demonstration could shape up as the last major stand by opponents to Israel's withdrawal from 21 Gaza settlements and four in the northern West Bank.
But protesters' defiance and willingness to tangle with the authorities could also foreshadow difficulties awaiting the government as it tries to remove 9,000 residents from the condemned settlements.
The government said it was determined to push through with its "disengagement" plan, which Prime Minister Ariel Sharon unveiled a year and a half ago.
"Ariel Sharon is not scared of 20,000 or 50,000 marching settlers," Vice Premier Ehud Olmert said.
Protesters had planned a three-day march beginning Monday in the southern Israeli town of Netivot and ending at the Kissufim crossing into Gaza, 15 miles away. The government outlawed the demonstration, stopped many protesters' buses and sent 20,000 police and soldiers to block the march.
Thousands of the marchers, many of them teenagers and families with young children, stayed overnight in Kfar Maimon, 12 miles from Kissufim, and Defense Minister Shaul Mofaz said they would not be allowed any closer.
"My orders are unequivocal: not to let this march reach Gush Katif," Mofaz told Israel TV, referring to the main cluster of Gaza settlements.
About 4 p.m., protesters surged toward the village gate, but police blocked their path. The sides traded punches, and two police officers were slightly injured. Police on horseback moved into the crowd; officers arrested 18 people.
"If they want to leave as individuals and go home, they are free to do so. But if they want to leave and march out as a group, we will stop them," said police spokeswoman Sharon Brown.
The marchers had hoped to break through the newly fortified Kissufim crossing into Gaza on Wednesday and march toward the settlements -- defying a government order last week blocking nonresidents from crossing into Gaza.
Thwarted, the demonstrators, numbering fewer than 10,000 by police count, turned Kfar Maimon into a protest village, holding sing-alongs and communal prayers. Portable toilets and drinking water were trucked in, and vendors sold sandwiches and sodas.
Many sought cover from the sun under tarps strung from trees. Nearly everyone sucked on orange ice pops -- the protesters' adopted color -- sold in commemorative Gush Katif wrappers. One teenager hawked an orange car deodorizer in the shape of Israel.
Speakers atop a van blared anti-pullout songs, one with the chorus "Jews don't expel Jews," punctuated by a guitar solo and a Doors-inspired keyboard track. A small crowd gathered around a man playing a ram's horn.
"It looks very pastoral, but under the surface there is a lot of anger and humiliation," said protester Avraham Weiss as he sat under a tree studying for a university exam on algorithms.
"It's been more than a year and a half (since the pullout was announced), and people feel they have been written off, have no way to express their feelings and beliefs," he said.
The government says the Gaza withdrawal would make Israel more secure and strengthen its hold on larger West Bank settlement blocs.
The settlers say that giving up Gaza after 4 1/2 years of violence would encourage more attacks by Palestinian militants.
In the West Bank village of Yamoun, two Palestinian militants were killed Tuesday in a gunbattle with soldiers surrounding their hideout, the army said. The army later bulldozed the building.
Israel has intensified arrest raids of militants since six Israelis were killed in attacks last week. Israel carried out several airstrikes last week, killing six Hamas militants.
The flare in violence also increased tensions between Hamas militants and the Palestinian security services, which promised to stop Hamas' rocket and mortar barrages of Israeli targets.
Palestinian police and Hamas gunmen clashed Tuesday in Gaza, exchanging fire, burning cars and lobbing hand grenades. Nine Palestinian police were wounded, authorities said.
The fighting erupted after the offices of two Hamas-affiliated research companies were burned down, residents said. In a separate incident, Palestinian police refused to stop at a makeshift roadblock in a Hamas stronghold, sparking a gunbattle, Palestinian authorities said.
Palestinian militants linked to the ruling Fatah movement put their gunmen on high alert and threatened to retaliate if attacked by Hamas.
Tensions between Hamas, which is using rockets to try to prove it is driving Israel out of Gaza, and Palestinian leader Mahmoud Abbas, who is trying to salvage a cease-fire with Israel, have risen, with Abbas under increasing U.S. and Israeli pressure to crack down on militants.