BANGKOK, Jan. 25 (Xinhua) -- Three police officers and three civilians were injured in a bomb blast in southern Thailand's Yala province on Friday morning.

Police said the bomb was detonated when the policemen were on patrol to protect teachers. Three local residents, including a young girl, who were on board a passing pickup truck, were also slightly injured.

Reports said security forces were dispatched to the scene. Authorities blamed insurgents for the blast.

Yala province, together with Narathiwat and Pattani, are the three southernmost provinces in Thailand that have been haunted by ethnic separatist insurgency since 2004. Bomb attack, gun shots are often reported in the restive area, with more than 7,000 people killed.