Police say suspected insurgents have detonated a motorcycle bomb that killed two security volunteers in Thailand's insurgency-plagued south, following overnight explosions that left one person wounded. Police Col. Tuanday Juthanan said Sunday that an explosive device hidden in a motorcycle went off in the commercial district in the city of Pattani before noon on Sunday. He said the explosion killed two security civilian volunteers who were on duty at a tower clock in the area and wounded 10 people, according to a report of the Associated Press. Tuanday said suspected militants on Saturday night planted seven bombs across Pattani city, two of which exploded. One person was injured. Security forces managed to defuse the rest.