Jeremy Wagstaff, Lhokseumawe – Hundreds of Indonesian migrants to Aceh have fled the province in recent days because of a terror campaign apparently conducted by the armed Free Aceh Movement.

Dozens of trucks laden with families and possessions plied the main road leading south from Aceh on Thursday. Refugees who reached the North Sumatran town of Medan earlier said they had been intimidated into leaving. Some said their houses had been burned and relatives had been killed.

"We are very scared. If Aceh becomes independent, our houses will be burned and we will be killed," said a 50-year-old man who fled Aceh with six members of his family on Wednesday.

The exodus isn't particularly new: Journalists in this Acehnese port town say it has been going on for months. But recent days have seen much larger numbers leaving. A group of refugees resting in the town of Idi said they had been threatened only in the past week. The military, which has been forced to scale back its presence in Aceh, is pushing for martial law in some parts of the province.

Ethnic, religious overtones

There is no sign yet of any major humanitarian crisis. But it is a worrying indication that what has been until now largely a grievance against the Indonesian government might be turning into a conflict along ethnic or religious lines. Among the main targets: immigrants from Indonesia's main island of Java.

Whether it is a mood supported by ordinary Acehnese isn't clear. For years, opposition to Jakarta was largely confined to exiles and a shadowy guerrilla group. But since the fall of longtime President Suharto in May 1998, frustration has deepened, and become more open. Many government and security buildings in this town are burned. Some 500,000 Acehnese rallied in the Acehnese capital of Banda Aceh earlier this month demanding a referendum on the country's future.

The move put pressure on newly elected president Abdurrahman Wahid, who this week promised a referendum within seven months. The key issue, though, is over what; it isn't clear whether Mr. Wahid will include the option of independence in any such referendum. The military, long responsible for holding Indonesia together, has expressed opposition to allowing Aceh to break free.

Indeed, Indonesia has worked for years to knit the archipelago together. The country is a patchwork of ethnic groups and religions, a mix boosted by a decades-old transmigration program to spread people from densely populated Java and Bali to outer islands. The result: At least 5% of Aceh's 3.8 million people in 1996 were born outside the province. Such immigration has sown longstanding local grievances over such things as land ownership and religion.

Protesters' deadline

Members of the Free Aceh movement have denied any attempt to push out such migrants. But refugees produce evidence to the contrary; leaflets claiming to be from Free Aceh warn of violence if Javanese and other non-Acehnese don't leave. And while migrants here appear nervous about discussing the matter, people who have left the province say there has been a coordinated effort to scare away all outsiders before the end of the month. The date appears to be related to December 4, the anniversary of an uprising in 1976 and the protesters' deadline for a government response on their demands for a referendum.

Many who have left say the people harassing and threatening them are recognizable Free Aceh members. "They are the same," said a 25-year-old woman.

There are few open signs the exodus is having an impact on ordinary life in Aceh. But migrants can be seen stacking everything from cupboards to satellite dishes atop towering trucks at many intersections, leaving whole communities virtually unoccupied.

And business is unlikely to remain unaffected: A 48-year-old man, Sumatra Muchtaruddin, said he has mothballed his machinery. His work: contractor to a massive gas refinery, PT Arun, co-owned by Mobil Corp. of the US. The home he left behind is on the fringes of the refinery, where walls, streets and street lamps are daubed with the same word: Referendum.

[Special correspondent Rin Hindryati contributed to this article.]