At least 15 pro-Islamic State militants were killed when Philippine troops launched air and ground assaults against a rebel bomb factory on Sunday, a military commander said.
Air strikes and artillery pounded an area in the Liguasan marsh in Maguindanao, where the Bangsamoro Islamic Freedom Fighters (BIFF) group had been making improvised explosive devices, said Brigadier General Cirilito Sobejana.
About 60 to 100 BIFF militants were in the vicinity when the assaults began before dawn, Sobejana said.
The military classifies the BIFF, which it say has 300 to 400 members, as a terrorist organization, along with the Abu Sayyaf and Maute groups.
The militants in southern Philippines have regrouped and were retraining and recruiting new members for future attacks after occupying the southern city of Marawi for five months last year, the military has said.