Ian Timberlake, Dili – An official has revealed new details about counterinsurgency operations two years ago that killed several pro-Indonesia militiamen and crippled their efforts to destabilize East Timor's transition to independence.

The military offensive was one of the most successful – and most proactive – undertaken under a UN mandate and may provide lessons for similar operations in the international war on terrorism.

Little was known about the military actions, one of which was code named "Crocodile," until ceremonies last month marking the handover of authority from the United Nations to a new East Timor government.

Sergio Vieira de Mello, the outgoing head of the UN Transitional Administration in East Timor, revealed the operations in an interview with foreign journalists shortly before the handover.

"We tried to learn lessons from the past, from Bosnia in particular, from Rwanda, from Somalia, and we hit hard. We never gave publicity to that," Mr. de Mello said.

The diplomat had supervised East Timor's transition to independence from 1999, when departing Indonesian troops – and the militia they created – destroyed most of the territory's infrastructure.

At least two multinational battalions spent several weeks in late 2000 hunting down between 150 and 200 militiamen who had penetrated deep into the central East Timor mountains during August and September that year, he said.

"That was indeed my worst moment," said Mr. de Mello, who feared a low-intensity guerrilla war that "would have put in jeopardy the entire transitional process here."

He did not reveal which countries participated in the joint offensive but Australia, New Zealand or Portugal were likely to have been involved.

On July 24, 2000, militiamen had shot dead a New Zealand soldier, Pvt. Leonard Manning, along the Indonesian border in southwestern East Timor. The next month, Pvt. Devi Ram Jaisi, from Nepal, died, and two peacekeepers were wounded in a militia attack east of Suai town, also in the southwest.

"Having been threatened, having lost our soldiers, we decided to revise our rules of engagement and to challenge them the way they deserved, and it worked. It took several weeks," Mr. de Mello said.

UN troops were permanently on the move in the mountains as they tried to surround the infiltrators, separate them from the local population, and deprive them of food, water and communications with "their bosses" in Indonesian West Timor, he said.