More than two weeks into a military operation aimed at bringing security and much needed relief supplies to tiny, devastated East Timor, aid agency officials and military commanders are stumped by a perplexing question: Where are the people?

As Australian troops have pushed into the territory's far western district, securing the border town of Balugade and the onetime pro-Indonesian militia stronghold of Balibo, they have encountered only a handful of people--at most, about two dozen refugees who have crossed the border into Indonesia proper to scavenge for food.

Here in Balibo, once home to 15,000 people, they found exactly one local resident--an elderly woman, believed to be deaf, who was left behind when the rest of the town fled.

Many people from the western districts of East Timor and the capital, Dili, were moved by force or by fear across the border into western Timor, in Indonesia, by violence that followed an Aug. 30 vote on East Timor's independence. The office of the U.N. High Commissioner for Refugees and other aid groups have estimated that more than 200,000 East Timorese may now be in western Timor, and they fear that many are being held against their will by militias opposing East Timorese independence.

But East Timor had a pre-crisis population of 850,000 people. Even accounting for the possibility that 200,000 or more refugees are in western Timor doesn't resolve the mystery surrounding the whereabouts of thousands more.

"In the back of the minds of the humanitarians is this question mark," said Michel Barton, a spokesman for the U.N. Office of Humanitarian Affairs, which is coordinating the relief effort. "We think we should have been seeing more people, and we don't have an answer to that."

He added that "there's a certain amount of anxiety behind that question. There haven't been discoveries of mass graves yet. So it's a question: Where are the people? We don't know yet."

A drive today from Dili in a military convoy, part of a U.N.-backed multinational peacekeeping force sent here last month, shows the extent of the depopulation of East Timor. During more than three hours, the convoy passed through once-crowded towns and villages--Liquica, Maubara, and Fatuboro--and encountered a total of six people. What remained in each village were scenes of near-total destruction: burned remnants of houses with their roofs caved in, empty shells of shops and mangled vehicles on the roadside. The only buildings left intact are the churches.

The view from the road confirms the reports from U.N. and military officials who have made helicopter tours over the area.

Here in Balibo where nearly 900 Australian troops have taken control of a 58-square-mile area, the commander of the operation, Lt. Col. Mick Slater, said his only disappointment was "the population is gone. And we really want the population to come back and try to rebuild the local community. That's what we're here for."

His troops have scanned the surrounding hills looking for people who may have fled there to escape the violence, but so far, not a single person has been found. "The hills are empty," Slater said. "The population just isn't here."

Ross Mountain, the U.N. coordinator for humanitarian affairs, said, "One assumes that there are literally hundreds of thousands up in the hills. . . . There's 600,000 people around someplace."

They are not, so far, in Dili. Even though refugees have started flooding back into the deserted capital from the surrounding mountains, the city now has fewer than 50,000 inhabitants, about half of its original population. The eastern town of Baukau was less affected by the two-week rampage by Indonesian soldiers and militiamen, but even there the numbers don't add up. There are usually 24,000 people in Baukau, but there now are about 7,000--4,000 original inhabitants and about 3,000 displaced people from nearby areas.

Getting the refugees in western Timor to return will help resolve the question. The U.N. refugee agency and the Indonesian government in Jakarta reportedly have reached agreement to allow refugees to return to East Timor if they wish. But so far, the accord has not been implemented, and there are no signs of any movement on the ground.

"There's been no change to the number of people we see here," said Slater, the commander of the western operation.

Slater said his troops at the border have talked with the few refugees who have ventured over on brief day trips in search of food. He said the refugees generally say they must return to the border town of Atambua in western Timor because their families are still there, and that the Indonesian authorities have told them it is safer to stay in western Timor.

He said some of those who come across may actually be militiamen posing as refugee scavengers to gain intelligence on Australian army positions. On one occasion, Slater said his troops confiscated "some militia-type weapons" the supposed refugees were carrying.

One who did emerge today was a 14-year-old boy, who told the Australian soldiers a harrowing tale of how he made his way here from Oe-Cusse, the East Timorese exclave located deep inside western Timor, on the northern coast.

The traumatized boy arrived on the beach at Balugade, describing how he made his way here by posing as a militiaman, joining militia gangs and hitching rides on militia trucks. He said he was sent here by the people of the exclave to give the multinational intervention force a letter pleading for help.

The boy was flown on a helicopter to Dili for more questioning and to be allowed to hand over his letter.

CAPTION: Lafu, a 14-year-old East Timorese boy, traveled through western Timor to reach Australian peacekeepers.