At least 10 people were killed in a powerful car bombing in the southern Philippines that officials linked to a pro-Islamic State group that tried to carve out a slice of territory in the south of the country last year.

Some counterterrorism experts said Tuesday’s attack showed that militant groups in the Philippines continued to pose a threat.

“At this point it is clear that even with Mindanao under martial law, the Abu Sayyaf Group remains capable of launching attacks,” said Joseph Franco, a counterterrorism expert at the S. Rajaratnam School of International Studies in Singapore. “Killing Abu Sayyaf group members is not enough if the community remains adversarial to the state,” he said.