Relatives of murdered school principal Gabriel Canizares buried Thursday the principal's severed head in Jolo, Sulu.

Authorities said they have yet to recover Canizares' body after finding the victim's head near a gasoline station in downtown Jolo early Monday. The principal was kidnapped by suspected Abu Sayyaf fighters in Barangay Tanum, Patikul town last October 19.

The Philippine National Police earlier filed criminal charges against Canizares' suspected kidnappers, identified as Basarun Aruk, Edimar Isnain and Abdulatip Jalmani.

Maj. Gen. Benjamin Dolorfino, chief of the Armed Forces' Western Mindanao Command, had said that Aruk is a leader of an Abu Sayyaf sub-group based in Patikul town.

Puno said the group's members are mostly minors or below 18-years-old and are believed to be drug addicts, citing police intelligence information.

Officials had said that a misunderstanding between the kidnappers and the negotiators, including the family of the school principal, could have led to the victim's beheading.

Puno said the kidnappers had relatives who died during the government's rescue operations for the three kidnapped members of the International Committee of the Red Cross in Sulu.