Army-backed militias have forced tens of thousands of East Timorese villagers from their homes -- shoving some over the border into other parts of Indonesia -- in a campaign apparently aimed at influencing the outcome of next month's United Nations-sponsored referendum on independence for the territory.

The United Nations, human rights groups and aid agencies have estimated that between 40,000 and 60,000 people have been driven from their homes, with thousands being held in town centers as virtual hostages to the militias, who hold indoctrination classes instructing them to vote against independence. The militias have confiscated radios to ensure that the villagers have no access to outside information about the ballot, say U.N. officials, aid workers and some of the displaced people.

Some of the people have fled into the surrounding hills and forests where they are suffering from lack of food and medicine and outside the reach of aid agencies. Many of those in the forests and camped along roadsides said they fled after being told they would be killed if they did not join the local militia, known in this area as the Besi Merah Putih (BMP), which means Red and White Iron, after the colors of the Indonesian flag.

"They came and said you all have to become Besi Merah Putih or you die," said Laurendo, 28, interviewed along the road in the Sarai area in the western portion of the territory, which is now home to about 3,500 displaced people. "Some joined, because they didn't want to die. Some ran into the hills. Others were killed. They just killed them right there, and left the bodies for others to collect."

Ian Martin, head of the U.N. mission in East Timor, known as UNAMET, said the issue of displaced people is one of the biggest hurdles to overcome in ensuring a free and fair vote next month.

He said they numbered "tens of thousands. The nature of the problem is such that you can't hope to put a number on it."

Another relief agency, whose officials asked that their names and organization not be published, put the number of displaced at "58,000 or more," including 11,000 who have sought refuge in the territory's capital, Dili.

The three western districts where the BMP holds sway are East Timor's most populous provinces. The militias rule with virtual impunity here, and U.N. workers have been attacked and threatened. And it is here that the anti-independence militias have threatened to carve off the western provinces and partition the territory, if East Timor votes for independence.

Last May, Indonesia signed an agreement at the United Nations setting up the August referendum that most analysts say is likely to lead to approval of independence, almost 24 years after Indonesian troops invaded the territory and began a violent occupation that has killed about 200,000 people. But even while agreeing to hold the ballot, the Indonesian military since the beginning of the year has been arming and supporting as many as 13 militia groups like the Red and White Iron, which have been terrorizing and trying to intimidate people into voting to remain a part of Indonesia.

"On the face of it, it seems they want to force people to vote for autonomy [and against independence], so they use violence, terror, even money," said Aniceto Gutteres Lopes, a Timorese lawyer who heads the Legal Aid, Human Rights and Justice Foundation in Dili.

Gutteres said his group has data putting the number of displaced people as high as 60,000. "People are unable to stay in one location," he said. He also said his office has received consistent reports of displaced people, mostly women, children and the elderly, who have been forced out of East Timor, across the border to the town of Atambua, in West Timor, which is part of Indonesia. The men, he said, "are left behind and forced to join the militia."

Villagers appeared to confirm reports of a campaign to prevent large numbers of East Timorese from voting. Santiago, 20, wearing a ripped white T-shirt, shorts and a headband, and armed with a machete, recalls how 30 people from his village were herded away -- including his mother and father.

"They took them away in an army truck," he said. "All the men were killed. Only the women and old people were spared." He said the militiamen told them their relatives were being moved across the border. And now Santiago and his friend, Maumeta, were standing along the road, on watch for any sign of militiamen approaching.

Dan Murphy, an American doctor working in Dili, was on the only aid convoy that went into the area to find displaced people. The convoy, including several U.N. vehicles, was attacked by a militia outside Likisia on the return trip. "The militias destroy any radio," he said. "You're killed or punished if you listen to a radio. The only information they want you to have is what they tell you."

"Western [East] Timor is decimated," Murphy said. "The entire population has just spread, running through the jungles. . . . You can argue about the numbers, but the fact is, the population has been decimated."

A trip to the region by three journalists confirmed the extent of the depopulation. Dozens of houses have been burned to ruin along a 30-mile stretch of road between the towns of Likisia and Sarai. The area now seems largely empty of people.

One village, called Guico, appeared especially hard hit; all that remained from a militia attack were the frames of buildings and a few collapsed corrugated tin roofs. On the wall of one burned-out shell of what may have been a guard shack, a scrawled line of graffiti reads: "Goodbye, Guico -- you are a village that will always be in my memory."

Some who fled have become so hungry and weak after months in hiding that they have begun the trek back home, despite the risk of encountering the militia. This reverse movement is what aid groups and others say has made a precise count of displaced people difficult.

The journalists last week encountered a group of 11 families making the return trip, after hiding in the forest since February. They came along the road with their belongings tied to their backs, piled in wheelbarrows, and strapped on horseback -- plastic containers and wicker mats, machetes for cutting wood and a few burlap sacks.

Among the group was a 28-year-old woman named Akalina, traveling with her husband, and a 1-month old baby who was listless and underweight.

"If we stayed in the forest any longer, we wouldn't have enough to eat," she said.

U.N. Secretary General Kofi Annan decided to allow voter registration to begin July 16 despite the problem of the displaced people. Even taking the lowest estimates, they represent more than 10 percent of the voting population of around 400,000.

To make sure the displaced are not left out, the world body is considering mobile voting registration teams that will seek them out. If they have lost their identity cards or other documents, the refugees will be able to sign an affidavit when they register.

In addition, the Japanese government has given 2,000 portable radios to UNAMET, and David Wimhurst, the U.N. spokesman in Dili, said some of those will be allocated to the displaced people.

For the moment, the displaced people here at Faulara are interested mainly in survival, and that means staying alert, being ready to move when necessary, and keeping one step ahead of the militias.

CAPTION: Residents of East Timor driven from their homes by militias emerge from the dense forest where they had fled in search of safety. The militias oppose independence for the territory and are trying to influence next month's vote.