Suspected Muslim insurgents have killed four paramilitary army rangers in an ambush in southern Thailand, in the latest high-profile attack in the troubled region.

Police Lt. Sailom Roduppo says a pickup truck carrying six rangers in Narathiwat province was blown off the road Thursday by an improvised explosive device. He says insurgents then opened fire, killing the four and wounding two others.

A Muslim separatist movement has been active for decades in Thailand's three southernmost provinces, the only ones with Muslim majorities in the predominantly Buddhist country.

More than 6,500 people have been killed since an armed insurgency flared up in 2004.