MANILA, Jan. 5 (Xinhuanet) -- Thirteen people were confirmed dead Monday in Sunday's powerful bomb blast at a town in the southern Philippine province of Maguindanao.

    Officials expected the number of fatalities to increase as the number of injured in the explosion has reached at least 67, the ABS-CBN news channel reported.

    The bomb, hidden in a motorcycle, was made from a mortar shell triggered by a cellphone, said Oscar Nantes, police chief of Parang town where the bomb explosion occurred Sunday afternoon near the entrance of a packed basketball court.

    Roadblocks have been set up around the town and police are trying to trace the owner of the motorcycle used in the attack.

    Among the injured was Parang Mayor Vivencio Bataga, who is believed to be the target of the bombing.

    The 57-year-old Bataga, who underwent surgery for his wounds, blamed political enemies for the attack.

    It is the fourth assassination attempt in a year against Bataga,a reelectionist in the May polls.

    The other victims were being treated at separate hospitals in nearby Cotabato city.

    The rebel Moro Islamic Liberation Front (MILF) denied involvement in the bomb attack, saying it would help track down the perpetrators.

    MILF spokesman Eid Kabalu said they and the government have an agreement to work hand-in-hand in arresting suspected and wanted criminals. Enditem