Jakarta – Three weeks of ethnic violence in an Indonesian province in Borneo have left hundreds of people dead and community leaders at a loss as to how to resolve the conflict.

In the only official comment on casualties, General Radin Hartono, the army Chief of Staff, said fewer than 300 people had died. Other sources say the toll could be in the thousands. Munawir Sjadzali, chairman of the national human rights commission, would only say "it is still far too premature to release casualty figures" after meeting government ministers.

The unrest in West Kalimantan is between the indigenous Dayaks and migrants from Madura, an island off the northeast coast of Java. It began on January 29 after a band of 40 masked men, believed to be from Madura, attacked a foundation that manages local Roman Catholic schools in Siantan Tengah, a district 40 miles outside the provincial capital, Pontianak. Two women were sexually assaulted.

Dayaks said that this unprovoked action broke a peace agreement the two communities signed after a week of violence at the turn of the year in which at least five people died. The extent of the Dayak revenge and the military's involvement is unclear. Henri Ofmcap, a Dutch pastor, said that Dayaks killed and beheaded up to 300 Madurese migrants in his three parishes alone. There have also been reports of widespread cannibalism by Dayak warriors, as they re-enacted centuries-old customs of butchering and eating their enemies.

At least 3,000 extra troops were flown to the area to contain the unrest. They prevented people leaving their neighbourhoods by setting up dozens of roadblocks. Witnesses claim that ten days ago troops shot at least 17 Dayaks who refused to disperse at a roadblock. Their bodies were buried in a mass grave in a nearby paddyfield.

Malaysia became so concerned that it closed its 12 border posts between West Kalimantan and its state of Sarawak for a week.

Edi Sudradjat, Indonesia's Minister of Defence and Security, has refused to comment on allegations of army brutality. On Monday he said the armed forces would continue to take stern measures against any troublemakers.

Dayaks have also set up their own roadblocks to prevent Madurese migrants fleeing to the safety of military bases.

One Dayak man, Ve Kader, said: "The Dayak people are saying to the Government that we are not prepared to accept the presence of Madura people in Kalimantan, particularly West Kalimantan. We are not going to rest until we have driven them all out of our rightful homeland."

The Madurese moved to West Kalimantan as part of the Government's transmigration programme, designed to relieve pressure on the densely populated islands of Java, Madura and Bali. They now make up the majority of the province's four million population.

Many people believe those who have fled are unlikely to return. Mr Ofmcap said: "Their homes have been looted and destroyed and their land taken by Dayaks. There is nothing for them, even if they did want to return. It is little short of 'ethnic cleansing'."