High school students arrested for their part in a violent riot this week in troubled Aceh province said they were asked to riot by strangers.

Two people were killed on Tuesday when security forces fired on rioters in the provincial capital, Lhokseumawe. Two days of violence, largely targeted at ethnic Chinese-owned businesses, led to the cancellation of a troop withdrawal from Aceh, once a centre of separatist rebellion.

North Aceh police chief Lieutenant-Colonel Iskandar said yesterday: "A hundred high school students have been detained for questioning. The students said they were asked by unknown men to riot."

One student said several men were waiting at his school when classes ended and told students to riot in the city, at the northern tip of the island of Sumatra. "The men threatened to beat us if we refused, so we went along. There were trucks waiting for us outside our school to transport us to the city centre," he said.

A resident said he saw a man handing out money on Tuesday night to five students in the city centre. "The riots were not started by the locals. We did not recognise many of the people who were rioting in the city," said one resident.

Aceh legislator Saifuddin Ilyas said the riots had been engineered by outsiders and that he had seen scores of students being unloaded from trucks to loot and damage shops, the official Antara news agency reported. "For example, during the riots, I saw the students looking confused as to which shops they should damage. This means they were outsiders brought into the area," Mr Ilyas said.

More ethnic Chinese residents were seen checking into guesthouses yesterday amid fears they might be attacked. Others remained camped at Lhokseumawe's military command post.