Devi Asmarani, Aceh – A simple bus trip at night can turn deadly in this violence-wracked province, where residents live in constant fear of being caught in vicious clashes between Indonesian troops and separatist guerillas.

I learned this the hard way during a road trip back to Medan, North Sumatra, from Banda Aceh on Saturday night. The bus set off with 16 passengers. Halfway through the 12-hour journey, only 15 of us were left.

During one of the road searches, a young man was taken away by armed members of the Free Aceh Movement (GAM) who suspected he was a cuak ("military informant"). He is now feared dead, like many other young men captured in road blocks set up by either GAM or the Indonesian troops.

The potentially deadly road checks at GAM's strongholds along the east coast of the province start typically with an ID search conducted by guerillas in military fatigues.

They look for suspicious targets – mostly young and healthy – looking men who could be a member of the military or the police. They also target passengers of Javanese ethnicity who they believe have been colonising them for decades.

I was among the three people who fell into these categories in our bus. My ID card was issued in Jakarta and I do not speak the Acehnese dialect.

The three of us were summoned out of the bus where we were interrogated at rifle point. I told my interrogators that I could not a get a plane ticket to Jakarta and had to leave through Medan.

One rebel, tapping his AK-47, responded coldly: "This is the ticket." The other woman, an academic from Jakarta who was doing some social work in the area, fared worse than me. While my South Sumatra origin helped soften them up, the fact that she was a Javanese almost made her a shooting target.

But a courageous Acehnese woman travelling with her came to her aid. The woman, who declined to be named, claimed that the Javanese woman was her sister-in-law and said she would rather have her throat slashed than let them take her away.

She was slapped by the rebel leader for "inviting people from Java to the land of the Acehnese". But she managed to save us. The third suspect, the 25-year-old man, was beyond help.

One of the rebels ordered his comrades to step aside and, cocking his rifle, started to get into a firing position with his weapon aimed at the man. They did not execute him there, but he was not released back to the bus along with us.

I went through two such terrifying checkpoints in the districts of Bireun and Sigli, and managed to stay alive both times, not because I was a journalist but because of my Sumatra ethnicity. One rebel even asked me to stay and join GAM's all-female guerilla unit.

Two hours later, at another checkpoint in Lhok Sukon, where thousands of troops guard major industrial facilities, members of the Police Special Forces (Brimob) made all the men in the bus step outside for a regular weapons check.

This episode of road checks illustrates what being an Acehnese feels like, constantly in fear of looking the wrong way or speaking the wrong language. In villages, troops sweeping through the villages beat up or execute young men, loot the houses and vandalise property.

At a GAM village I visited last week, a woman still suffering from the shock of having her village raided by troops told me: "Whenever the ba'i ['Indonesian military'] arrives here, I tell my husband to hide in the mountain. "I have more of a chance to survive than him."

Another young man said: "The troops always suspect people who look good and dress nicely as a GAM member; now I dress like a farmer." A mental patient in Banda Aceh who suffered psychological trauma after being tortured severely by troops, along with two other mental patients, said he would rather stay in the hospital than return to his village. In his village, he said, the lives of people like him are expendable.