The vanguard of an international peacekeeping force arrived in East Timor today on a mission to end the 2 1/2-week rampage of bloodletting and destruction that erupted in the territory after residents voted overwhelmingly for independence from Indonesia.

A Hercules C-130 transport plane carrying mostly Australian troops landed this morning at the airport in Dili, East Timor's capital, and was followed by four more within two hours. Nine more flights are scheduled to ferry troops, vehicles, weapons and other equipment to Dili today, and by this evening leaders of the U.N.-sponsored mission say they expect 2,500 soldiers -- about a third of the authorized 7,000-member force -- to be in place around Dili.

Troops from Australia, Britain and New Zealand who were on the first aircraft quickly secured the perimeter of the small airfield, while others headed for the city's port facilities to clear the way for the imminent arrival of nine warships carrying troops from more than a half-dozen nations, along with armored vehicles and helicopters. Several hundred U.S. troops will take part in the operation, chiefly to provide logistical support and intelligence gathering.

Leaders of anti-independence militia groups responsible for most of the killing and devastation in East Timor had threatened to oppose the peacekeepers, but most of them are said to have been withdrawing from Dili in recent days, and the first peacekeepers were met cordially by about two dozen Indonesian troops.

Australian Maj. Gen. Peter Cosgrove, who met with the Indonesian military on Sunday to coordinate the landings, said before that meeting that his forces would "respond robustly" to any armed threat by the militias. And U.N. Secretary General Kofi Annan, who has warned the militias not to confront the peacekeepers, said the force is prepared to strike back if attacked. "I would hope the militia will not try to take them on, because they will defend themselves," Annan said on CNN's Sunday news program "Late Edition."

Cosgrove conferred in Dili with Maj. Gen. Kiki Syahnakri, the Indonesian commander there, who said he expects his forces to hand over formal control of the territory to the U.N. force by Saturday. Cosgrove said that he would "relay back to my higher authorities that the cooperation has been first class."

The Indonesian military opposed East Timorese independence and recruited and supplied the militias with weapons to try to disrupt the vote. But Indonesian troops have been ordered by President B.J. Habibie to make way for the international force, and Syahnakri said his forces also will help in a cleanup operation in the ruined city.

As they broaden their zone of control, the largely Australian peacekeeping contingent will find a devastated landscape in which thousands of homes have been destroyed, their occupants nowhere to be found, and virtually every business vandalized or burned.

The arrival of the full peacekeeping complement will clear the way for a massive humanitarian effort to bring food, medical aid and security to the hundreds of thousands of East Timorese who fled the violence that began after the Aug. 30 independence vote. There is said to be no food, water, electricity or sanitation service in East Timor, and thousands of displaced people are hiding in the mountains, scavenging for whatever food they can find.

Refugee accounts that have emerged from Dili and the countryside include allegations of massacres by the militias of people suspected of favoring independence, and there have been calls for prosecution of those responsible.

Arriving with the rest of the peacekeeping force will be officials of the U.N. Assistance Mission in East Timor, who were evacuated last week after enduring a siege at their compound in Dili, where nearly 1,500 displaced local people had sought safety. Those people also were airlifted to Australia.

Australian Prime Minister John Howard said in a televised address Sunday that the peacekeeping mission "could be long and protracted . . . and the conditions could well be violent and dangerous. There is a risk of casualties."

Howard took note of Indonesian objections to Australia's leading role in the multinational force, stemming from the Jakarta government's belief that Australia promoted the independence of East Timor and is not a neutral party. "Our soldiers go to East Timor as part of a great Australian military tradition, which has never sought to impose the will of this country on others but only to defend what is right," he said.

The multinational force is expected to stay in East Timor until the United Nations can establish some form of local civil administration and the territory can provide its own security. With a voter turnout greater than 98 percent, East Timorese voted overwhelmingly to end Indonesia's 24-year rule over the territory and its 800,000 people.

East Timor -- which constitutes half the island of Timor, about 1,600 miles from Jakarta -- was a Portuguese colony until it was invaded by Indonesia in 1975 and incorporated into that country a year later, an action that is not recognized by most nations.