Tomi Soetjipto, Jakarta – Indonesian troops opened fire to disperse a mob near a separatist's home in the troubled province of Aceh whom they claim masterminded weekend violence in which nine people died, witnesses and the military said on Tuesday.

"On Monday the unit raided a house of Ahmad Kandang of the separatist Free Aceh group," Colonel Johny Wahab, military commander of the industrial town of Lhokseumawe on the northern tip of Sumatra island, told Reuters.

"He was responsible for Sunday's violence," Wahab said, adding there were no casualties in the raid. The troops failed to find Kandang but locals said they saw 15 people being taken away in a military truck.

The raid followed a riot on Sunday near Lhokseumawe when troops opened fire on an angry mob killing nine civilians. The army says separatist snipers started the shooting.

Witnesses said that in Monday's raid, security forces fired warning shots to disperse a crowd of hundreds who had surrounded the separatist's house in Lhokseumawe, some 1,600 km northwest of Jakarta.

One local journalist said that the attack took place at around 5.00 pm on Monday. "Security forces blocked the main road from five to six. None of us could go out of the town between that time," he said.

Colonel Wahab said that the town was back to normal on Tuesday though a number of shops were closed. "The town is still quiet, it seems people are still afraid to go out," he said. Locals said troops were still patrolling the city centre.