[Herald Correspondent Louise Williams goes behind the lines in the fighting in Kalimantan, Indonesian Borneo.]

Sei Duri, West Kalimantan: Two nights ago the tribal war party came - boys just out of childhood, the black mark of battle upon their foreheads, the feathers of swiftness tied to their heads, the torches and knives of destruction firmly in their grasp.

They came, the survivors say, like the spirits of the dead called up by the Dayak tribes to wage war against the people of the Madura, Muslim migrants to the tropical rainforests of Kalimantan which for millennia belonged to the indigenous tribes.

One minute they were there, then they were gone.

The patches of charred wood and twisted metal were still smouldering, the odd corpse of a goat or cow tossed aside, where the homes of the Madurans once stood. Hundreds of men, women and children ran screaming into the town, but the shop owners closed their doors against their fear. So they kept on running to the mosque. Many, many died, the locals say.

This is the most terrifying of conflicts: a war fought hand to hand, and a war in which there can be no compromise. This is a war of traditional weapons, of magic and superstitions and absolute destruction.

Once the Dayaks, the headhunters of Borneo, have declared war they cannot turn back: they must drive the Madurans from their land and burn their houses to the ground, they say.

Yesterday, the shops remained barricaded, the refugees already gone, taken by the military to a safe camp about 30 kilometres further north along the narrow coastal road which cuts through the damp mangrove flats. Along this highway there are many burnt-out houses and many twisted tales of revenge. The army is now in control but a few hundred metres inland the road blocks begin, gangs of jumpy youths patrolling the deserted ruins.

"May we pass, may we pass," we ask over and over again, handing cigarettes through the window. "Do not get down, do not take photos," our Dayak guide says. We do not know who these people are. We do not know if they are angry. Outside the remaining homes sit offerings of yellow rice and chicken blood to protect the survivors from harm. Lolong, our driver, says he has prayed and gathered up yellow rice for his pockets to keep us safe.

These young men on the road say they are "Melayu", not Madurans. They are not targets, but they are scared. They have painted "Melayu" across their homes. Some are damaged, but none burnt down.

Many migrant groups, both Christian and Muslim, Chinese and Malay, have come to the forest of Kalimantan to trade, to mine gold and to work on the plantations and roads. But it is the indigenous Dayaks and the Madurans, from eastern Indonesia, who have reached this bloody impasse.

In minutes of snatched conversation the young men tell us that the war party came with boys to do the burning, some as young as 12, armed with traditional knives and bows and arrows, their foreheads marked with soot. They do not want us to stop. Some say the attackers were spirits, raised from the dead. Other talk of magic Dayaks who would not die, their blood unable to be shed with the blow of a curved knife.

The war is, says a Dayak priest, a matter of culture. The Madurans, he says, are hot-tempered, frequently armed, and believe a crime must be avenged with blood. The Dayaks, he says, believe that an offence against an individual is a crime against the tribe and must be "paid back". So overwhelming are the blood debts of the three months of fighting that it is difficult to imagine how the war can be stopped.

"For the Dayaks, killing is something unusual," says a Government official of Dayak descent. "If you go into a Dayak's house you must leave your weapon outside, but if you insist on bringing it in you must be punished under their laws.

"What I really worry about is the Dayaks believe that they must destroy everything of their enemy - their people, their homes and even their trees. It has to be total destruction, there is no compromise.

"The Dayaks have a motto: You pay blood with blood, you pay life with life."

This may be true. But it is also a matter of politics and policy.

This is a scene the Indonesian Government does not want us to see. Journalists have been ordered not to travel here and local newspapers have been directed not to publish pictures and descriptions of the carnage. There is no official death toll, just a range of wild guesses mounting into the thousands.

Rapid economic development and Government programs to relocate millions of Muslim farmers from densely populated islands like Madura and Java to the remote forests of the indigenous tribes have created explosive rifts in many of the outer islands.

Economic policies at a national level have had little regard for the impact on people's lives of crop monopolies, forced evictions for development programs, entrenched corruption and a lack of Government accountability.

Kalimantan is rich in gold, coal and palm oil, rubber and timber plantations, most of which are owned by outsiders and run by migrant workers. Only one regional head in the whole of West Kalimantan is Dayak, and in some majority Dayak towns the Madurans are in control.

"I warned the Government that something like this would happen," says an official.

"I believe we need to adjust development policy. In reality policies don't support the Dayaks. The Government says they should go to school but a school in a Dayak area might have only two teachers for six classes. This is because the teachers are Muslims and don't like living near the Dayaks, who eat pork and keep dogs.

"So the effect is the Dayaks' human resources are very low and they don't have the qualifications to compete."

It is then, he says, that the Dayaks revert to their own laws: harsh, bloody and uncompromising.