Chief Inspector Eduardo Marquez, Midsayap police chief, said the suspect, Habib Mangundatu Abo, an ethnic Maguindanaoan, was nabbed with the help of witnesses in the town’s public market.
Witnesses tagged Abo as the one who hurled a fragmentation grenade at worshipers in a mosque inside the compound of the National Irrigation Administration (NIA) in Barangay Villarica, Midsayap.
The attack resulted in the deaths of two NIA executives, engineers Macmod Mending and Omarkais Mamalak, Region 12 director and provincial irrigation chief of Maguindanao, respectively, and a preacher named Datukali Ismael.
However, Abo, a resident of Midsayap, denied having perpetrated the bombing, admitting though that he was at the mosque then but only to perform the mandatory Friday prayers.
NIA insiders earlier expressed suspicions that "internal squabbles" among the agency’s officials might have led to the grenade attack.
Abo told Catholic radio station dxMS via a mobile phone that he was innocent of the charges.
"I was surprised how the witnesses could just point their fingers at me as the culprit," he said in the dialect.