Two hotels and a disco were targeted in the most recent attacks in Sungai Kolok in Narathiwat province, a BBC correspondent reported.

Police said two of the injured were in serious condition.

No one immediately claimed responsibility for the attacks although the area has been a hotbed of Islamist separatism since 2004, the report said. Since then, associated violence has killed more than 2,500 people in the region.

Security patrols and police checkpoints throughout the country were stepped up in the past week with the memory of the New Year's Eve 2006 Bangkok bombings that killed three people, local media said.