Suspected Muslim militants have abducted six sawmill workers in a southern Philippine region where a recent military offensive killed at least 24 of the rebels, military officials said Tuesday.

Gunmen seized the workers Monday in a far-flung village in Butig town in the predominantly Muslim province of Lanao del Sur and government forces were taking steps to secure their freedom, army Col. Nilo Samarita said.

It was not immediately clear what the motive was for the abduction of the Christian workers.

The largely unknown Maute group of militants staged a brazen attack on an army outpost in Butig town in February, sparking a major military offensive and days of fighting that killed 24 militants and six soldiers, one of whom was beheaded.

Army troops captured an encampment of the militants where armbands bearing the symbol of the Islamic State group were found, military officials said.

A number of small Muslim militant factions in the south, home of minority Muslims in the largely Roman Catholic country, have expressed support to the Islamic State group on online videos but the military says there has been no evidence of any direct and active collaborations.