Security authorities detained two suspects in Thailand's restive south Friday after a roadside bomb attack and a following gunfight caused injuries of two paramilitary rangers.

The violent attack took place in Narathiwat's Sri Sakorn district at around noon Friday while a six-men squad was traveling on three motorbikes as a routine patrol, the website by The Nation newspaper reported.

The bomb was set off manually through an electrical wire that was tied to a five-kilogram explosive and run into the wooded area about 150 meters from the roadside, it said.

The gunfight between the two side lasted for about five minutes before the militant retreated back into the wooded area.

The country's deep South comprises mainly the three southernmost provinces -- Yala, Pattani, Narathiwat, and some parts of Songkla province.

Insurgent violence has killed over 3,500 people in the deep South since its resurrection in January 2004.

(Xinhua News Agency January 23, 2009)