Cotabato City, Philippines (dpa) - Philippine police have recovered a homemade bomb outside an elementary school in a southern province, a regional military spokesman said Friday.

Major Armand Rico said police officers found the explosive device late Thursday near the gate of the school in Carmen town in North Cotabato province, 960 kilometres south of Manila.

Rico said bomb experts defused the bomb, which was placed in a sack and was composed of ammonium nitrate with fuel as explosive device, a 9-volt battery as power source and a bulb as initiator.

Security forces in North Cotabato and nearby provinces have been on heightened alert since last month following fierce fighting between government troops and Moro Islamic Liberation Front (MILF) rebels.

The hostilities were triggered by a Supreme Court decision stopping the signing of a deal that would have expanded an existing autonomous Muslim region on Mindanao, the Philippines' southern island.

More than 200 people have been killed and more than 500,000 displaced in the fighting. (dpa)