The deployment came amid warnings that anti-independence militia groups were stepping up their activities.

Soldiers raided the headquarters of one militia group, confiscating weapons including home-made guns, machetes and knives.

But there are many more weapons on the island in the hands of both pro- and anti-independence groups.

The commander of the peacekeeping force, Major-General Peter Cosgrove, said the provincial capital, Dili, was not yet secure.

Eurico Gutteres, commander of one of the most notorious anti-independence militia, was quoted by Indonesia's official news agency as saying East Timor might be plunged into a civil war.

The BBC's Angus Roxburgh: "Some militia gangs are packing up"

In the Baucau operation, Australian Black Hawk helicopters flew 150 troops into the northern coastal city.

It was the first major advance outside Dili since the UN-backed peacekeepers arrived on Monday.

Baucau has a larger airport than Dili, which will eventually allow the force to speed up its deployment into East Timor.

Anger at refugee return

The BBC's Jonathan Head: "The international force faces a formidable task"

Maj-Gen Cosgrove said the pro-Jakarta militants may be stepping up their random attacks because refugees, who had been in hiding, are returning to Dili.

He said they wanted to show "all is not yet secure".

People flooded back from the mountains to Dili on Tuesday, after peacekeepers moved into the city.

Thousands of people were displaced and whole towns destroyed when the militias, backed by Indonesian troops, went on the rampage to punish those who voted for independence last month.

Click here to see a map of latest developments in East Timor

Residents of East Timor greeted the arrival of the peacekeepers

Maj-Gen Cosgrove said the situation was particularly dangerous because of the random nature of the attacks.

The mutilated body of Sander Thoenes, the Jakarta correspondent of the London Financial Times, who also worked for Dutch news magazine Vrij Nederland, was found on the outskirts of Dili on Wednesday - apparently murdered by the militias.

Two other foreign journalists had a narrow escape when their car was ambushed, forcing them to hide until they could be rescued by Australian troops.

Looting

Queueing for food amid shortages

Returning refugees have ransacked government-run warehouses in Dili, carrying away sacks of rice and sugar, and barrels of cooking oil.

Australian peacekeeping forces managed to regain control of the warehouses, but only after most of the food had gone.

The refugees said they could not wait for international aid to arrive.

The international charity, Medecins Sans Frontieres, has criticised the intervention force for not allowing more humanitarian relief into East Timor.

It complained that the peacekeepers gave space on flights for journalists while limiting access for aid agencies.

Aid flights were suspended as the military build-up got under way because of a lack of space at Dili airport and a shortage of aircraft.

Despite the return of some refugees, thousands remain in hiding in forests and mountains.

Commander Peter Cosgrove of the UN Peacekeeping force: "We are imposing some levels of control"

People sheltering in the mountain town of Dare say about 20 people there have died from malnutrition. They are still too afraid to return to their homes in Dili.

UN spokesman David Wimhurst said food airdrops had been delayed for a second day as military aircraft poured into the airport.

Nearly half of the 7,500-strong peacekeeping force was expected to be on the ground by Wednesday.

The force has so far secured Dili port, the airport and the UN headquarters. Several warships have also arrived.

Indonesian Security Minister Feisal Tanjung said President BJ Habibie will soon lift martial law in East Timor, and hand responsibility for security in the territory over to the multinational force.

Intimidation

An Australian military spokesman said Indonesian soldiers were expected to have withdrawn completely from the territory by Sunday.

East Timorese pro-independence leader Jose Ramos Horta said he had urged Indonesian Foreign Minister Ali Alatas to protect the thousands of East Timorese refugees in West Timor, which remains under Indonesian control.

"We know that power in Indonesia does not lie with the foreign minister, but it is to him that we can address our concerns," Mr Ramos Horta told the Portuguese radio station TSF.

His remarks came after UN High Commissioner for Refugees Sadako Ogata expressed concern over reports of intimidation of East Timor refugees by Indonesian forces in West Timor.

Mrs Ogata said the organisation would send missions to East and West Timor to assess the needs of refugees.

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