MANILA -- Defense Secretary Delfin Lorenzana said authorities were confirming if a Moroccan national working with the Abu Sayyaf was behind the "suicide" attack at an Army checkpoint in Basilan.

Lorenzana, however, refused to link the attack to the Islamic State, which had claimed that one of its jihadists, a Moroccan, was behind the blast that killed 10 on the spot.

• Islamic State claims Basilan blast

The driver of the van that contained the explosives was among those killed. Prior to the incident, the military received reports that a Moroccan national tried but failed to convince the Abu Sayyaf to mount suicide attacks.

Lorenzana said authorities were "80 percent sure" that the van driver was the wanted Moroccan national. Quoting witnesses, he said the driver was fair-looking and could not speak the dialect.

The suspect planned to attack a gathering with some 4,000 children in downtown Lamitan, but turned it into a "suicide" mission after he was stopped near a Scout Ranger detachment.

The Moroccan was trying to avenge the death of one of his two children. He was also monitored on Jolo Island, the defense chief said.

"He was trying to convince the local ASG in Basilan to conduct suicide bombing, wala namang sumasama e. Luckily, wala pang matapang na Pilipinong mag-suicide bombing e," Lorenzana told reporters.

(He was trying to convince the local Abu Sayyaf in Basilan to conduct a suicide bombing, no one joined him. Luckily, no Filipino is brave enough to carry out a suicide bombing.)

Asked if it could be considered a suicide attack, Lorenzana said: "That time siguro, suicide bombing na sya, kasi wala na syang magawa e, mahuhuli na sya e, so nagsuicide na lang sya."

(That time, maybe, it was a suicide bombing because he had no choice. He will get caught so he committed suicide.)

"But that was not the intention. Siguro ang intention nya dalhin nya yung vehicle sa isang lugar na makainflict ng maximum casualty, alis sya, at a distance i-detonate nya from a distance," he said.

(But that was not the intention. Maybe, the intention was to bring the vehicle to a place where he can inflict maximum casualty. He will leave, then detonate it from a distance.)

Lorenzana said the Moroccan national's face was encircled and marked as a "martyr" in photos recovered from Jolo.

"Meron pang agam-agam kung siya talaga iyun eh, pero sa akin mukhang qualifications point that he is the guy," he said.

(There are still doubts if that's really him, but for me, the qualifications point that he is the guy.)

Security forces are monitoring at least 6 foreign terrorists in Mindanao, Lorenzana said.

Terror suspects from the Middle East, according to intelligence reports, would stay in Indonesia first before going to the Philippines, he said.

Lorenzana said the explosives used in the Basilan attack were different from the ones used in previous bombings.

The blast was so powerful, it bore a crater in the ground and only the van's engine block was left, Lorenzana said.

Authorities are looking into reports that the materials used to make the explosives came from Sabah in Malaysia or Indonesia, he said.