COTABATO, Philippines - At least six breakaway Muslim rebels have been killed in a fresh fighting on Friday night in the southern Philippine province of Maguindanao, a military official said Saturday.

Col. Prudencio Asto, spokesman for the military's 6th Division, said the skirmish erupted after elements of the Bangsamoro Islamic Freedom Fighters (BIFF) harassed a military detachment in the town of Guindulungan in Maguindanao on Friday.

A firefight ensued, according to Asto, leaving six dead on the enemy side.

The military also said BIFF rebels behind a series of recent attacks on military detachments in Maguindanao last week are being coddled by their former colleagues in the Moro Islamic Liberation Front (MILF).

"Some of the members of BIFF men have relatives in the MILF. Blood is thicker than water. We know that some are now hiding in the camps of the MILF," Asto said.

Mohaqher Iqbal, chief negotiator for the MILF, said in a separate interview he could not deny or confirm the military's pronouncement as majority of BIFF members have relatives in their organization.

"We are calling on BIFF who were not involved in the recent fighting...our doors are still open. They can go back to us anytime," Iqbal said.

According to the latest report of the Protection Cluster in Mindanao, some 9,000 families or 45,526 people have been displaced in the fightings in seven towns of Maguindanao, which erupted on Aug 5 when BIFF members simultaneously raided eight military positions in the region.

The BIFF, the armed wing of the Bangsamoro Islamic Liberation Movement led by Ameril Umbra Kato, is composed of former MILF members who are not covered by the existing ceasefire agreement between the MILF and the government.