A Philippine military spokeswoman says a bomb explosion killed at least two people and wounded eight others on Basilan island, a stronghold of Al Qaeda-linked militants.

Lt. Stephani Cacho says the improvised bomb exploded late Friday in front of a popular fast-food restaurant and near a public square in Isabela township. She says the blast may have hit a power line, cutting off electricity in the area.

Cacho says the incident is still under investigation and authorities have no suspects yet.

Basilan is a stronghold of Abu Sayyaf, which is on a U.S. list of terrorist organizations. The group on Thursday freed a Filipino Red Cross worker after 10 weeks of captivity in the nearby island of Jolo but is holding two other hostages — a Swiss and an Italian.