At least two people have been killed and 15 others wounded in two bomb blasts in the southern Philippines. Provincial police said improvised explosive devices were used in both incidents. In one of the blasts, a 60-millimetre mortar exploded near the Commission on Audit building in the North Cotabato region. A mobile phone was used to trigger the device. No-one has claimed responsibility for the bombings.The Al Qaeda-linked Abu Sayyaf Group and the rebel Moro Islamic Liberation Front operate in Basilan and North Cotabato provinces.