Police in Thailand's violent south say suspected Muslim militants killed six people and wounded another Friday in coordinated attacks.

Authorities said the first attack took place overnight, when the suspected militants shot and killed a worker at a rubber plantation in southern Narathiwat province.

Officials said the suspected insurgents then bombed a truck carrying six defense volunteers who were responding to the shooting. Authorities said five of the volunteers died when the bomb – buried in the road – detonated. The sixth defense volunteer suffered severe injuries.

Southern Narathiwat province is one of three Muslim-dominated provinces bordering Malaysia.

More than 4,600 people have been killed in violence in southern Yala, Pattani and Narathiwat provinces since a Muslim insurgency began there in January of 2004.