United Nations officials today warned a visiting U.S. congressional delegation that East Timor's army-backed militias have access to sophisticated weapons and are planning for full-scale war if, as expected, they lose the Aug. 30 independence referendum.

The bleak assessment prompted the delegation to ask the United Nations to send armed peacekeepers to the troubled territory to prevent violence from endangering the election.

The militias, which are opposing independence, have terrorized the districts near East Timor's border with Indonesia proper--kidnapping and threatening independence supporters and taking away voter registration cards, the U.N. officials told the delegation led by Sen. Tom Harkin (D-Iowa).

As part of what the United Nations called these "preparations for war," militia members have been moving their relatives across the border to Atambua. In the troubled area of Maliana, officials said, residents were already fleeing, with militia families moving to Indonesia proper and independence supporters running to the surrounding forests and hills.

The United Nations has its own evacuation plans if the situation deteriorates after the voting. In Maliana, which one U.N. official called "a powder keg," the plan calls for a vehicle convoy to transport about 80 people to West Timor, two hours away.

Here in Suai, Harkin told a group of 2,500 pro-independence refugees who have taken shelter at a church compound that he would urge President Clinton and the United Nations to dispatch peacekeepers to Timor before the vote.

"We're going to be asking our government and the United Nations to be providing some peacekeeping forces here," Harkin said. "From what we've seen, it's necessary to have somebody here to stop the intimidation."

In Suai, the delegation, which also included Sen. Jack Reed (D-R.I.) and Rep. Jim McGovern (D-Mass.), got a first-hand look at the intimidation, and the involvement of local officials; the refugees at the church had been without water for more than a day, after local authorities cut the supply. Also, a food convoy destined for the camp had been held up in the Timorese capital of Dili, where Indonesian authorities refused to give the group permission to leave.

The delegation later met with Herman Sedyono, Suai's top Indonesian official, who was attending an outdoor rally of anti-independence forces. Sedyono denied cutting the water to the refugees and promised to allow food aid inside.

The refugees cheered Reed when he declared: "The vote is more powerful than the army!"

In briefings here and in Maliana, the delegation heard the same complaint--that the militia is backed by locally based elements of the Indonesian army, and that the police, who are responsible for the security of U.N. officials and facilities, are powerless to intervene.

Ian Martin, the head of the U.N. mission in East Timor, this week called for the removal of Indonesian army personnel responsible for directing militia activities. "In many cases, it is lower TNI [Indonesian army] ranks who are actively involved as members of militia groups," he said.

Several U.N. officials said they believe President B.J. Habibie and the armed forces commander, Gen. Wiranto, may be committed to a peaceful settlement of the long-standing Timor issue, but the change of attitude in Jakarta may not have been translated to those in the field.

CAPTION: U.S. Sen. Jack Reed (D-R.I.) receives a statement about anti-independence militia violence from East Timorese refugees taking shelter at a church.