Southern Tagalog police director Chief Superintendent Jesus Versoza said the nine communist rebels were killed by pursuing government forces.
Versoza said the identities of the slain rebels have yet to be established. He said several firearms were recovered at the scene.
The clashes took place in Barangay Nalisbitan, Labo, Camarines Norte, near the boundary of Tagkawayan, Quezon Saturday afternoon.
The rebels reportedly attacked an Isuzu Elf van driven by a certain Elmer Darca of Unisan, Quezon.
Troops were immediately dispatched to the scene following reports that the fuel truck was torched by the rebels.
Versoza said the firefight began when soldiers and policemen cornered the communist rebels in Barangay Nalisbitan in Labo town, near the Quezon-Camarines Norte boundary.
Following the encounter, police and military forces were alerted for possible retaliatory attacks by the NPA in the area, Versoza said.
The NPA is the armed wing of the Communist Party of the Philippines.