Local officials confirmed the Pentagon gang members were killed during the two-hour fire fight with Army intelligence agents searching for Norman Sia, a car trader abducted by the group in Cotabato City last week.
There were no casualties reported on the government side but one soldier, Cpl. Edward Dionat, of the Armys 6th Infantry Division-Reconnaissance Company was wounded.
Another soldier and a militiaman, whose identities were withheld by the authorities, were also reported missing.
The military said they launched operations in the area following intelligence reports that the bandits took Sia with them at the vicinity of Barangays Nimao in Datu Piang and Linunangan in Talitay, known lairs of the Pentagon Gang, which is led by Tahir Alonto and Mayangkang Saguile.
Police and military investigators said the clashes in Barangay Nimao erupted when Pentagon gang members ambushed a team of soldiers.
The military said the kidnappers have put up stiff resistance prompting them to call for OV-10 bombers to "soften up" the area before the final assault. John Unson