The victims Reynerio Chua, William Ditros, Bernalyn Minted and Babylin Tiburcio are now confined at the Cotabato Regional Medical Center in Cotabato City.
Lt. Col. Julieto Ando, civil-military relations officer of the Armys 6th Infantry Division, said the victims were bound for Barangay Rente, a hinterland area in North Upi, when they were ambushed.
Ethnic Tedurays in North Upi have long been opposing all logging operations in the town.
About two years ago, a fuel lorry of a logging company in North Upi was set on fire. John Unson