MANILA/JOLO: Fifteen people including 10 police officers were wounded in two separate blasts that hit a police camp in a restive southern Philippine province, police said Saturday.

The first explosion was caused by a grenade near a mosque at the police compound in the Sulu provincial capital of Jolo late Friday, according to a police report. It was followed minutes later by a more powerful blast from a homemade bomb.

Those injured in the blast included five civilians, including three children, and 10 policemen.

No group has claimed responsibility for the blast, but police suspect the Abu Sayyaf group.

Police last week killed a suspected Abu Sayyaf member allegedly involved in kidnappings in the eastern Malaysian state of Sabah, close to Sulu.

Successive blasts targeted the mosque inside Camp Kasim on the island of Jolo early evening Friday, an initial grenade attack followed by a bomb explosion less than 10 minutes later 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.

Rosalyn Aya-ay, a shopkeeper and policeman’s wife, said she found her husband sprawled on the ground after the first explosion and took him to the camp hospital, though he was not seriously injured.

“When I returned I found my two daughters wounded by the second blast. I was scared and I had a hard time finding an ambulance to carry them,” she told AFP.

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

It was the second bomb attack on Camp Kasim since 2010, when a Christmas Day blast wounded six people.

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

Police investigators combed through the scene of the blast Saturday, which was about 10 meters from a guarded entry gate, but would not say how the attackers had smuggled the explosives into the camp, an AFP photographer on the scene said.

The families of policemen assigned to the camp also live inside the facility.

The Abu Sayyaf 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 IS militants fighting in Syria and Iraq.

The Abu Sayyaf is estimated to number about 400 fighters, and has turned to ransom kidnappings and extortion to survive following setbacks from US-backed military offensives.

The group is still holding a Dutch birdwatcher who was seized three years ago, and a southern Philippine town mayor abducted from her home last month.