The first foreign peacekeepers have arrived in Dilli, the capital of East Timor.
Thousands of locals welcomed the group of Australian commandos who are there at the request of the East Timorese government.
The government appealed for international help after riots by disaffected former soldiers led to the worst violence in the country since it gained independence from Indonesia in 1999.
UN officials say the situation in East Timor has calmed considerably.
But Australian Prime Minister John Howard told his parliament that the troops were on a risky undertaking.
Portugal, the former colonial power in the region, has also pledged to send paramilitary police, while Malaysian defence officials have confirmed that troops and police will be deployed.
The trouble began last month when nearly half the troops from the 1,400-strong military were sacked for deserting their barracks after complaining of regional discrimination over promotions.
A 600-strong breakaway force, made up mainly of soldiers from the west of the island, has been involved in sporadic gun battles with the rest of the armed forces over recent weeks.
Officials say opposition groups have exploited the situation, sparking attacks and resisting mediation.
Despite a population of under one million and a land mass only slightly bigger than the Bahamas, East Timor has been the scene of a complex international tug of war and bloody independence struggles for more than 30 years.
It was invaded in 1975 by Indonesia, which held the territory until 1999, when a vote for independence descended into violence orchestrated by pro-Jakarta militias.
Australia led a UN-backed intervention force to stop the bloodshed, and the territory was run by the UN until independence in 2002.