The Free Aceh guerillas are vowing to fight to the death as Indonesian troops step up their crackdown in the province. Lindsay Murdoch talks to those in the firing line.

Nobody suspected Syaiful of being a spy, let alone an executioner. In March, he drove his jeep for the first time into Blang Meurandeh village, deep inside the mist-shrouded mountains of Sumatra's north-western tip. The villagers, who are usually distrustful of outsiders, quickly came to like Syaiful, a man in his mid-30s, because he would always listen to their problems and give them a lift down the mountain. They dubbed him "orang halus" – a cultured, kindly man.

The soldiers, heavily armed and with their faces blackened, arrived without warning, jumping from two trucks and swarming over the village.

The people had no time to escape. It was early morning and Teungka Bantaqiah, the 55-year-old village guru, was asleep in the two-storey wooden boarding school where he taught a pure form of Islam to dozens of followers.

His wife Farisah, 32, woke him and told him Indonesian troops had arrived. "Everybody in Aceh fears the Indonesians and he grabbed a kitchen knife," she says, sobbing. "But I told him to put it down and go outside." By the time Bantaqiah walked unarmed down the stairs with his students and two of his sons, Sufi, 6, and Usman, 29, who was born to a former wife, the soldiers had herded the men into a group outside the school.

At first, the terrified villagers did not recognise Syaiful. He was wearing the uniform of Kostrad, the elite strategic reserve unit of Indonesia's armed forces, which has launched a new offensive to crush a growing rebellion in Aceh, Indonesia's staunchly Islamic oil-rich province.

Syaiful pushed to the front of the soldiers as one of them smashed a pistol into Usman's face and he fell against his father. Telling her story in detail to the Herald this week, Farisah says Bantaqiah shouted, "Allahu Akbar" (God is Great) three times and raised his arms in protest. A smile creased Syaiful's blackened face as he fired two shots at Bantaqiah. But when the teacher did not fall immediately – which later prompted talk he was invincible to bullets – another soldier raised a self-propelled grenade launcher and fired into his chest, splattering pieces of his body onto the school wall. Usman was also cut down.

Farisah says her son Sufi disappeared under falling bodies as the massacre started, one of a series in Aceh which human right groups say has been carried out by an occupation force that kills, rapes, burns and loots with impunity.

"The recent dramatic escalation in human rights violations in Aceh, including dozens of extrajudicial executions, disappearances and arbitrary arrests, flies in the face of the Indonesian Government's commitments to address human rights problems," says Amnesty International.

When the shooting stopped, 32 men lay dead, says Farisah, whose account is supported by human rights activists. Miraculously, her young son survived, suffering only a bullet wound to his right foot.

The soldiers then forced some of the villagers to lift another 25 wounded onto their trucks, saying they would take them to hospital. Two days later, their bodies were found dumped in a ravine eight kilometres away. Many of them had been slashed, as well as shot, indicating they were tortured.

The youngest victim was 18, the oldest 55. Farisah says the soldiers' commander told her, after the village women were searched and assaulted, that the Blang Meurandeh was a suspected base for the rebel Free Aceh Movement, which first declared independence for the province in 1976 with the aim of establishing an Islamic state.

"He told me they were looking for weapons," she says. "But they didn't find any and I asked him, 'Are you happy now?'" Human rights groups say evidence of the massacre is overwhelming, although there is no official investigation under way.

But the real motive for the killings is murky. Villagers say Blang Meurandeh grew marijuana for the military, which human rights activists believe controls most of the illicit trade of the drug in Indonesia. "The military will never leave Aceh because it is too lucrative a business," an activist says.

Early this year, B.J.Habibie, the Indonesian President, promised to withdraw troops from Aceh, try those responsible for human rights violations and end the siphoning of more than 90 per cent of the province's annual income. But like other promises of broad autonomy and the right to become an Islamic state, made by former presidents Sukarno and Suharto, they have not been honoured.

Sitting in a safe house with her two children, Sufi and seven-year-old Mahadi, Farisah denies her husband's role in the drug trade and says: "If I had a knife, I would cut the hearts out of those soldiers. If my husband was guilty, why didn't they take him away and put him through the courts? Why kill him and the others on the spot?"

With the rebels intensifying a nine-month offensive against Jakarta's rule, Aceh is in a state of siege. Although the eyes of the world are on East Timor, at the other rim of the archipelago far worse atrocities are happening. The fiercely independent Acehnese have never been pacified this century.

As hundreds more troops arrive in the province each day, with orders to shoot on sight, more than 140,000 villagers have fled their homes. They are living in appalling conditions in makeshift camps that are strictly controlled by the rebel movement. Every day, more refugees arrive at the six main camps, where conditions are deteriorating rapidly. Aid agencies fear outbreaks of serious diseases, as families squat in crude shelters, with little food and medicines. The conditions are said to be as bad as those endured by the Vietnamese refugees who poured into South-East Asian countries in the 1970s and 1980s.

At least 220 people have been killed in Aceh since May, when a 3,000-strong special anti-riot force was sent to the province by the armed forces chief, General Wiranto, the man widely tipped to be elected Indonesia's vice-president in November.

Both sides of the Aceh conflict acknowledge the existence of a so-called "third force" of troublemakers believed to have links to the armed forces. Although there is scant hard evidence, many analysts suspect they are former members of the Kopassus special forces.

Hundreds of buildings, including schools, have been destroyed across the province. And almost every day dozens of soldiers sweep through villages, seizing those they suspect of supporting the rebels.

Neither side is willing to negotiate. Habibie and Wiranto refuse to recognise the Free Aceh Movement, whose leader, Hasan di Tiro, 75, lives in Stockholm.

Yet there is widespread sympathy with many of the separatists' demands, even in some sections of the military. A local commander, Colonel Syarifuddin, says the Government's handling of social, economic and cultural problems caused the crisis. "This must be changed. The Government must give greater attention to Aceh because there will never be a military solution here," he says.

Arbitrary killings are just about a daily occurrence in the province, and evidence of mass graves has become commonplace.

Last week, Aceh was paralysed by a general strike in protest at the military's announcement of a fresh six-month campaign to wipe out the Free Aceh Movement. It will involve 11,000 police, soldiers and civilian militia hunting down the "disturbance movement", as the national police chief, Roesmanhadi, calls the rebels. Anyone not in the uniform of any of the official security forces and caught carrying a firearm will be shot on sight, he says. The police spokesman, Brigadier-General Togar Sianipar, is even more blunt. "This special operation will take pre-emptive and repressive measures to rebuild the society," he says.

But the rebels are extremely well organised and appear to have the support of most Acehnese. Only a few kilometres from a squad of heavily armed soldiers patrolling roadside villages, Abdullah Syafi sweeps into a small village on the back of a motorbike, waving his Kalashnikov rifle in the air in a show of defiance for a small group of foreign journalists. Sitting cross-legged on a mat in a traditional house, the Free Aceh Movement's senior commander launches into a tirade against the "Javanese imperialists" who, he says, have raped and murdered the Acehnese for decades.

"We have yet to wage real war," he says. "We want to play the rules of the international community. But the Javanese are stupid. The name 'Indonesian' is fake. We can fight them and we will fight them to the end." Syafi, 43, dismisses comparisons between Aceh and East Timor, where Jakarta is allowing the United Nations to organise a ballot giving East Timorese a choice between autonomy or independence. "We demand freedom. There is no alternative, so we are very different," he says.

The rebels have so far not attacked any of Aceh's huge industries, notably the P.T. Arun liquified natural gas plant, part-owned by Mobil, in the industrial city of Lhokseumawe, 1,600 kilometres north-west of Jakarta. Few analysts doubt that the movement, with an apparently steady supply of arms from Cambodia, has the ability to sabotage revenue flows to Jakarta.

"We are not stupid," says Syafi. "We respect the foreign people working there. But then, if the international community does not pay attention to us, maybe we will attack. There are no rules in war." The Free Aceh Movement is itself deeply divided. One side wants a referendum to decide the future of the Acehnese. But the hardliners, such as Syafi, a former teacher who has been fighting since his early 20s, insist the Indonesians must withdraw completely. "We will defend this place until our last drop of blood," he says.