At least four people were killed and four others injured in a bomb blast in southern Thailand, a police official said in Bangkok on Friday.
The homemade device loaded with three kg of explosive material exploded on Thursday night near a checkpoint in Pattani city, the official told EFE news.
The authorities, who immediately began a search and capture mission, blamed Muslim insurgent groups operating in the region.
More than 6,500 people have died in southern Thailand since the Muslim separatist movement resumed its armed resistance in 2004 after being dormant for nearly a decade.
Light weapon attacks, murders and bomb blasts are frequent in the provinces of Pattani, Narathiwat and Yala, despite the deployment of around 40,000 security forces and a state of emergency, declared in 2005.