COTABATO, Philippines — Dozens of militants aligned with the Islamic State group opened fire on a Philippine army detachment and burned a police patrol car in a southern town but withdrew after troops returned fire, officials said Friday.

There were no immediate reports of injuries in Thursday night’s brief attack by the Bangsamoro Islamic Freedom Fighters in Datu Piang town. Nevertheless it sparked panic among residents and rekindled fears of a repeat of a 2017 militant siege of southern Marawi city that lasted for five months before being quelled by government forces.

“We are on top of the situation. This is just an isolated case,” regional military commander Lt. Gen. Corleto Vinluan Jr. said in a statement.

Security officials gave differing statements on the motive of the 30 to 50 gunmen. Some said the militants targeted Datu Piang’s police chief over a feud but others speculated that the militants wanted to project that they are still a force to reckon with by attacking the army detachment in the center of the predominantly Muslim town.

Officials denied earlier reports that the militants managed to seize a police station and burn a Catholic church.

When reinforcement troops in armored carriers arrived and opened fire, the militants fled toward a marshland, military officials said.

The Bangsamoro Islamic Freedom Fighters is one of a few small armed groups waging a separatist rural insurrection in the south of the largely Catholic nation. The groups opposed a 2014 autonomy deal forged by the largest Muslim rebel group in the south with the Philippine government and have continued on and off attacks despite being weakened by battle setbacks, surrenders and factionalism.

The armed groups include the Abu Sayyaf, which has been blacklisted by the United States and the Philippines as a terrorist organization for kidnappings for ransom, beheadings and bombings.