HAT YAI: Police say two teachers were killed and one was injured in a bomb attack believed to have targeted security forces in Thailand's insurgency-plagued south.

Police Col Patta Madawah says suspected Muslims insurgents detonated an explosive Wednesday as a car carrying three teachers passed by a hospital in Narathiwat province.

He says investigators believe the militants were targeting a police vehicle in front of the teachers' car.

Two police officers were wounded in the attack.

More than 5,000 people, including more than 150 teachers, have been killed since an Islamic insurgency erupted in Thailand's three southernmost provinces in 2004.

Wednesday's explosion came weeks after Muslim separatist negotiators agreed to attempt to halt violence during Ramadan as part of ongoing peace talks with the Thai government.