Ivan Libero, a 32-year-old East Timorese militia member with a silver earring and fashionable sunglasses, says he is ready for peace. But with his green military pants, camouflage vest and a pistol strapped to his waist, he looks ready for war.

"Falintil hasn't surrendered their weapons, so I'm not going to surrender my weapon," said Libero, referring to the guerrilla group that has been fighting for independence from Indonesia for 24 years. "I'm prepared for what will happen."

After Monday's referendum on East Timor's political future proceeded with only a few scattered incidents--and with more than 98 percent of East Timorese defying the threat of violence to cast their votes--it was widely hoped that militiamen like Libero might cease their campaign of terror and fade away once they realized that intimidation didn't work.

But today the militias--who oppose independence for East Timor in favor of enhanced autonomy within Indonesia--were back on the streets of Dili, the capital, and elsewhere around the territory, throwing into doubt the future of the U.N.-sponsored process to bring an end to one of the region's most intractable, if largely hidden, disputes.

Here in Dili, the Aitarak ("thorn") militia, of which Libero is a member, threw up roadblocks and ransacked the office of the main pro-independence group, the National Resistance Council of East Timor, or CNRT. They briefly took over the airport, preventing about a half-dozen East Timorese from boarding the only outbound commercial flight. And they reappeared on Dili's streets, at the waterfront and around the Hotel Tropical, which has become their base, openly brandishing sidearms and knives in defiance of a peace agreement their leaders signed just last weekend.

In the most serious incident outside Dili, militia members in Gleno, southwest of here, laid siege to the town, burning 10 houses, firing shots and attacking a U.N. helicopter that came to pick up the election ballots. They held a 17-car U.N. convoy, with 150 people, as virtual hostages for several hours. The militiamen were demanding that the U.N. staff in the convoy turn over about 50 East Timorese among them.

The standoff ended just before nightfall, and the convoy, with all staff members, arrived in Dili.

Gleno, a militia stronghold, is where a Timorese U.N. staffer, Joao Lopes Gomes, was stabbed to death Monday on his way home from the polling place, raising fears about the safety of U.N. workers living in militia-controlled areas. A U.N. official reported today that two other Timorese workers were missing and feared dead after the Monday incident.

Foreign observers of Monday's voting, who returned today to the capital from western districts, reported that the militia had reinstalled blockades on the road between Maliana and Liquica after those makeshift checkpoints had been dismantled in time for Monday's vote. Their return today indicated that, with the balloting over, the militias had resumed their tactics.

The Indonesian police, who are supposed to be in charge of security for East Timor, were nowhere to be found in some places where there was militia activity; in others they refused to intervene or colluded openly with the militia.

For example, just before the CNRT office was attacked, a witness said, "The police drove off and waved, and two minutes later the militia attacked the office." At the airport, militia leader Eurico Guterres announced he was blocking Timorese from leaving, but it was unclear how he and his forces had entered the facility and gained access to the departure lounge.

An Indonesian official today condemned Guterres' threatened blockade as a violation of people's freedom of movement. "Eurico Guterres is not the government," said Foreign Ministry spokesman Dino Patti Djalal, who urged all sides to "remain calm."

Indonesia invaded East Timor in 1975 and annexed it a year later, setting off civil strife that has killed more than 200,000 East Timorese.

Another major headache for the United Nations emerged today when East Timorese political leaders opposing independence announced that they were withdrawing from the electoral process and challenging the results of the vote because of what they called "irregularities" by U.N. staff members.

A spokesman for the faction, Basilio Dias Araujo, complained that the United Nations prevented members of his group from observing the ballotting, that Timorese working for the United Nations instructed people to vote for independence and that the ballot boxes could have been stuffed with extra papers.

As a result, he said, the vote was "meaningless, not legitimate, unjust and not transparent at all."

The autonomy advocates' withdrawal disrupted a planned U.N.-sponsored meeting this afternoon that was supposed to bring together all of East Timor's warring parties in a show of post-ballot unity. The meeting did go on, but without the major players on the anti-independence side.

It was uncertain tonight whether that faction's latest move was a prelude to the civil war that many had predicted, or a bit of last-minute political maneuvering.

"My own feeling is that this is the last gasp," said a Western diplomat.

But on Dili's tense streets, scores of militiamen seemed to be girding for war. As they prepared for a funeral--one of their own, they said, who was killed by pro-independence forces on the eve of the election--they expressed confidence about the results of the ballotting. "If it's free and fair, and there's no manipulation, we will win," said Libero, surrounded by a dozen of his black-shirted comrades who nodded in agreement.