LAMITAN, Philippines >> A bomb-laden van driven by a suspected Abu Sayyaf militant went off in a powerful blast Tuesday that killed 11 people, including a soldier, five militiamen and the driver, in a brazen attack that reignited terrorism fears in the southern Philippines.

Regional military spokesman Lt. Col. Gerry Besana said six army scout rangers and a militiaman were wounded in the explosion after dawn outside an army militia outpost that tore a crater on the road and damaged the outpost in Lamitan city in one of the worst terrorist attacks in the country this year.

Militiamen, who have been alerted on possible bombings, stopped the van at a checkpoint in Colonia village, where the bomb went off, military officials said.

“If he triggered the bomb, he was probably waiting for a more opportune time to inflict harm on a bigger number of people,” Besana said by phone, referring to the driver, who died in the blast. “That’s their death wish — the more, the merrier.”

The Philippine government condemned the terrorist attack, calling it a “war crime.”

Investigators have yet to determine if the bomb or bombs were being carried in the van or the vehicle had been turned into a car bomb, Besana said, adding it was also unclear if the explosive was remotely detonated or was set off by the driver in a suicide attack.

Militiaman Gregorio Inso, who survived but lost his wife to the blast, said the van was flagged down for inspection by his colleagues outside the militia outpost. When the driver apparently wanted to restart the engine, the militiamen looked inside and saw suspicious strands of wire inside the van and called a group of scout rangers.

“When the rangers were approaching, the vehicle suddenly exploded,” Inso said. “When I looked again everyone was dead.”

Military spokesman Col. Edgard Arevalo said the driver, who witnesses described as looking scared and who did not respond to questions at the checkpoint, could be an Abu Sayyaf militant under a ruthless commander, Furuji Indama, who recently plotted bombings in predominantly Muslim Basilan.

Government forces have also been put on alert in the south, scene of decades-long Muslim separatist unrest, after President Rodrigo Duterte signed a new autonomy agreement last week with the biggest Muslim rebel group in the country.

The peace deal has been opposed by much smaller but violent extremist bands like the Abu Sayyaf and others which have aligned themselves with the Islamic State group.

The country’s south remains under martial law, which Duterte declared last year to deal with a five-month siege by Islamic State group-linked militants in southern Marawi city that left more than 1,200 mostly militants dead, displaced hundreds of thousands of villagers and sparked fears that the Islamic State group was gaining a foothold in Southeast Asia amid its battle defeats in Syria and Iraq.

The Abu Sayyaf, which was founded in the late 1980s in Basilan, has been blacklisted by the United States and the Philippines for bombings, ransom kidnappings and beheadings. It has been weakened by government offensives and surrenders but remains a national security threat