BANGKOK, March 17 (Reuters) - Six teenagers have been arrested in connection with a minibus attack that killed eight people in Thailand's rebellious Muslim south last week, an army spokesman said on Saturday. Some of them confessed to being involved in last Wednesday's ambush by green-clad gunmen on the bus in the southern province of Ytala, Colonel Acra Tiproch told Reuters. He declined to give details of the charges, or name the youths who had relatives in the Yaha district where the attack occured. "We have evidence that they were involved in the attack," Acra said. The six were arrested on Thursday when authorities imposed a curfew on the Yala districts of Bannangsta and Yaha. The army also ordered everyone in Yala, Narathiwat and Pattani -- the three far south provinces where the bulk of the separatist violence that has killed 2,000 people since 2004 has occurred -- to report overnight guests to the authorities. And it said anyone caught wearing clothes similar to army or police uniforms would face up to 10 years in jail. The minibus attack infuriated Buddhists, a minority in the far south, where Muslims who speak a Malay dialect have long complained about being treated as second-class citizens. A military crackdown would be popular among Thailand's overwhelming Buddhist majority, even though the government installed after a bloodless coup in September says it is pursuing a policy of reconciliation to restore peace. The Wednesday attacks took place on the anniversary of the founding of the separatist Barisan Revolusi Nasional (BRN), or National Revolutionary Front, which the government had feared would be marked by an increase in violence.