Senior Supt. Federico Dulay, chief of the North Cotabato Police Office, said that although the pattern is the same, the investigators are still trying to determine the identities of the groups and verify if they are one and the same.

Last week, three bombing incidents rocked North Cotabato.

Last Wednesday, a hand grenade exploded inside a videoke bar in Poblacion, Carmen town, just a few meters from the area where the Philippine-US military training and exercises were being held. One person was injured in the blast.

Last Friday, an M-203 grenade exploded at a vacant lot in Barangay Kagaya, Kabacan.

The bombing in Barangay Kayaga was the third since last December. On the same day, an improvised explosive went off inside a baggage counter in an establishment in Midsayap, injuring one customer. (Malu Manar)