DAVAO CITY, Philippines, Sept. 2 (Xinhua) -- At least 15 people were injured in a grenade blast in southern Philippines late Saturday, military officials said on Sunday morning.

Major Jacob Obligado, commander of the army's 10th civil- military operations battalion said the incident happened in Fatima village, Paquibato district, Davao City around 9:25 p.m. local time.

Obligado told Xinhua by text message the grenade went off as villagers watched a circus performance during festivities there. The scene of incident is about 30 km from the city proper and is closest to nearby Panabo City, Davao del Norte province to the north.

"Soldiers providing security in the area reported 15 civilians were wounded and rushed to Rivera Hospital in Panabo," the military spokesperson said, adding police authorities were still investigating the possible suspects and motive of the incident.

One of the far-flung districts in regional capital Davao City, Paquibato is a known lair of the leftist New People's Army.