New York – The United States warned Indonesia's military on Friday not to overthrow the country's new president and to cooperate with national and UN investigations into human rights abuses in East Timor.

Failure to cooperate will only increase pressure overseas for an international tribunal to try those accused of carrying out a wave of terror in East Timor, said Richard Holbrooke, the US ambassador to the United Nations.

His warning came amid speculation that some of Indonesia's top generals, angered by efforts aimed at prosecuting them for human rights abuses, may be planning a move against President Abdurrahman Wahid.

"We have seen news reports about the possibility of military coups in Indonesia," Holbrooke said in a conference call with US and Indonesian reporters Friday morning. "We would view with the greatest possible concern any such event. It would do Indonesia immense, perhaps irreparable damage," he said.

On Thursday, Wahid fired armed forces spokesman Major General Sudradjat, who had publicly denied that the military would carry out a "conventional coup" but had confirmed that the generals intended to pressure the 3-month-old administration to stay out of military affairs.

Sudradjat is believed to be a close ally of General Wiranto, the former military commander and now Wahid's senior security minister.

"Any Indonesian army officers or any military officers who are thinking of military adventurism have forgotten that we are now in the 21st century," said Holbrooke. "The damage to Indonesia would be unbelievable."

Holbrooke later told reporters at the United Nations that it was vitally important for Wahid, Attorney General Marzuki Darusman and others to ensure that the military generals responsible for the violence in East Timor be prosecuted.

"The Indonesian generals should know that their own efforts to thwart internal accountability and openness and inquiry are only going to result in greater pressure," for a tribunal similar to those for the former Yugoslavia and Rwanda, Holbrooke said.

A government human rights investigation has accused Wiranto and other top commanders of permitting the frenzy of violence that swept East Timor in September after the territory voted to secede from Indonesia, which had occupied it in 1975.

A separate UN human rights commission also has submitted a report on atrocities in East Timor, and three UN human rights investigators have recommended that the Security Council establish a tribunal if Indonesia fails to carry out effective trials.

Holbrooke accused the military of hampering both probes. He also cautioned pro-Jakarta militias based along the border with Indonesian-held West Timor not to "test" the UN troops who will soon replace the Australian-led emergency force sent to East Timor to halt the post-referendum violence. "Anyone who tries to use the transition as an excuse to create chaos again will suffer very severe consequences," he said.

After a briefing by UN officials to the Security Council, Holbrooke said the militias continue to inflict physical terror and psychological intimidation on the estimated 100,000 East Timorese in West Timorese refugee camps, preventing many from returning home.