Chris McCall, Jakarta – Detained independence activist Muhammad Nazar has a simple message for Indonesian President Abdurrahman Wahid: turn up the heat on Aceh and you may stir up a war you cannot win.

Speaking haltingly by telephone from his cell hours after President Wahid visited Banda Aceh on Tuesday, Nazar said he was suffering from a fever, had no window in his cell, was often forced to urinate within it, and had at times received death threats from members of the security forces.

Nazar's lawyer made a request for the President to come to his cell during Mr Wahid's lightning visit to the strife-torn northern province. Police refused to convey the request.

Nazar explained what he would have told him: "Don't make any declaration of war. Jakarta must give an opportunity for Aceh to struggle peacefully, not play around with ideas like military or civil emergency. That will make Acehnese people angry and they will fight."

Acehnese had fought Dutch invaders for decades and were never defeated by them, he said. "Wahid himself should appreciate the aspiration of Acehnese to determine their own fate. And he should watch his inferiors, make sure they do not act brutally."

For more than a decade, Aceh has been rocked by fighting between security forces and the separatist Free Aceh Movement. From 1989 to 1998, it was a "military operations area". During that time thousands of Acehnese were tortured, maimed, raped or killed by Indonesian troops.

Recent demands for a new state of emergency have provoked unease in Aceh, where a faltering truce is due to run out on January 15. In an ominous turn yesterday, Defence Minister Mahfud Mahmodin said direct peace talks with the rebels would end then. Not that talks have delivered even a semblance of peace: nine people were killed in a spate of shootings across the province yesterday. Sounding near to tears, Nazar said his experience since his arrest on November 20 had reconfirmed his view that Indonesia was a neo-colonialist power.

Nazar is no guerilla. He heads a civilian mass movement seeking a peaceful referendum on independence. He has been detained under anti-subversion laws not invoked since the days of former president Suharto. The former despot often used them to jail his political opponents.

Many say the present Government is doing the same with Nazar. After a series of summonses, he finally went to Banda Aceh's city police headquarters to answer questions concerning activities of the Information Centre for Aceh Referendum (Sira), which he heads. This body, led by students and recent graduates, has campaigned for nearly two years for an East Timor-style referendum on independence.

After a day's questioning, he was suddenly arrested and transferred to provincial police headquarters. He has been interrogated three times. The questions have included why he used phrases such as "the Aceh nation" and "neo-colonialism".

He also was asked about opinion polls conducted by Sira. The polls showed an overwhelming majority of Acehnese wanted a referendum – something Jakarta has firmly rejected – and would vote for independence.

Nazar has been allowed a small radio and some books and newspapers. He has to ask a sentry to take him to the toilet and is allowed regular visits from only his family and lawyer.

Nazar expects to face trial but does not know when. He is accused of subversion over a boycott on Indonesia's independence day celebrations on August 17.