Banda Aceh – Indonesian police said Saturday they had arrested a sixth rebel peace negotiator in the restive province of Aceh amid an intensifying anti-guerrilla crackdown by security forces.

Sofyan Ibrahim Tiba, a member of the separatist Free Aceh Movementwho was involved in talks with Indonesian officials, is accused of subversion and faces life imprisonment, Aceh police spokesman Commissioner Sudarsono told

Police arrested Tiba at his home, five kilometers north of this provincial capital, at 10:30pm Friday. "The arrest was based on the results of the questioning of the five GAM negotiators we arrested on July 20," Sudarsono said.

Tiba sat on a joint GAM-Jakarta security monitoring committee set up under the auspices of Switzerland's Henry Dunant Center as part of a ceasefire agreement, dubbed a "Humanitarian Pause", in May 2000.

Indonesia unilaterally decided to suspend the committee and to dissolve a parallel committee overseeing humanitarian affairs, after the failure of renewed peace talks in Geneva in early July.

Tiba was suspected of carrying out subversive activities and fomenting hatred against the Indonesian government, Sudarsono said. "Police questioned him straight after his arrest and detained him at provincial police headquarters," he added.

Tiba's family said he was resting in his bedroom when three carloads of police turned up at their home. "We heard knocks at the door and got scared and turned out the lights. They kept knocking so we opened the door, and several policemen came in asking for my father," said one of Tiba's sons, who asked to accompany his father to the police station. "They let me come. We were taken to the local [elite police] Brimob base," he told AFP. However, police ordered him to go home when they began questioning his father. The five negotiators arrested in July are still in detention at Aceh's police headquarters.

Indonesian security forces have been stepping up efforts to crush the rebels since April when then president Abdurrahman Wahid gave the green light for escalated military operations. The crackdown on the peace negotiators began as the national parliament in Jakarta, supported by the police and military, accelerated moves to impeach Wahid and replace him with his deputy, Megawati Sukarnoputri.

Wahid was dismissed and Megawati, an avowed nationalist who is considered an ally of the military, installed on July 23. The GAM rebels have expressed fears that the new government will take even harsher action as Megawati, the daughter of founding president Sukarno, seeks to maintain Indonesia's territorial integrity.

In the first half of this year alone more than 1,000 people have been killed in Aceh, in what observers say is the highest killing rate in more than two decades of fighting between GAM and government troops. The GAM has been fighting to turn Aceh, a province rich in oil and gas on the northwestern tip of Indonesia, into an independent Muslim state since the 1970s.