Jolo, Philippines: Fifteen people including 10 police officers were wounded in an attack on a mosque on a remote Philippine island long plagued by Islamic militancy, officials said Saturday.

Successive blasts targeted a mosque on the island of Jolo -- an initial grenade attack followed by a bomb explosion that was intended to target police who rushed to the scene, local authorities said.

‘It seems the (first) explosion was set up to draw responders as the target,’ the provincial police chief Senior Superintendent Abraham Orbita told reporters.

Three of the five civilian causalities injured in the first explosion were children and 10 police officers were wounded by the improvised explosive device that detonated less than 10 minutes later, police said.

No group has claimed responsibility for the attack, which occurred in the provincial capital of Jolo, a mainly Muslim island in the south of the predominantly Catholic Asian nation.

The island is a known stronghold of Abu Sayyaf, a small group of a few hundred Islamic militants founded in the 1990s with seed money from Al-Qaeda.

The group gained international notoriety for some of the worst terror attacks in Philippine history including bombings and kidnappings of Christians and foreigners for ransom.

Filipino security forces have for more than a decade received counter-terrorism training assistance from the United States, which sent military advisers on short-term deployments to Jolo and other areas.

However the Philippines has struggled to contain the group, whose leader last year pledged allegiance to Islamic State militants fighting in Syria and Iraq.