A bomb exploded outside a warehouse in Isabela City in Basilan at around 11 p.m. on Thursday.
The explosion occurred outside the warehouse owned by Basilan Department of Public Works and Highways (DPWH) district engineer Soler Undug.
Undug claimed the Abu Sayyaf was behind the explosion, saying he refused to give in to the bandits' demands. The DPWH has an ongoing project in Tuburan town, which is being targeted by the Abu Sayyaf for extortion.
According to police, the blast was caused by an improvised explosive device.
Police said no one was injured in the explosion.