I

ntense fighting between Philippine troops and a little-known Muslim group apparently inspired by the Islamic State group has killed 54 militants and two soldiers, officials said Monday.

Regional military spokesman Maj. Filemon Tan said the operations against the Maute group began last Thursday in southern Lanao del Sur province's Butig town and were still continuing. He said nine soldiers had been wounded in addition to the two who were killed.

The military fired artillery and launched air strikes "to get the criminals" behind the beheading last month of two sawmill workers, Tan said. He said the workers were forced to wear orange robes while being beheaded, like victims of the Islamic State group. Four other sawmill workers were freed after their employers negotiated with the captors.

Troops have not retrieved the militants' bodies, but based the count on intelligence reports and on sightings of bodies being carried away by other militants, Tan added.

In February, the group attacked an army outpost in Butig, sparking days of fighting that killed 24 militants and six soldiers, one of whom was beheaded.

Authorities said the group has used black clothing with the symbol of the Islamic State group in Syria and Iraq.

Several small militant factions in the southern Philippines, the home of minority Muslims in the largely Roman Catholic country, have expressed support for the Islamic State group in online videos, but the military says there is no evidence of any direct, active collaboration.