MANILA, March 9 (Xinhua) -- Heavy fighting between government troops and some 50 militants in the southern Philippines has resulted in the deaths of 12 militants, a military spokesman said on Friday.

Army Capt. Arvin Encinas said the clash broke out around 6 a.m. on Thursday in Lower Salbu, a village in Date Saudi Ampatuan town in Magunindanao province.

He said 23 other rebels belonging to the Bangsamoro Islamic Freedom Fighters (BIFF) and a soldier have also been wounded in the clash.

"Available fire support were launched to support the engaged troops against an estimated 50 BIFF bandits under Commander Peni of Karialan faction," Encinas said in a statement.

"Our soldiers have been vigilantly guarding the entire Central Mindanao in order to constrict the firefight in specific engagement areas and continue to pursue the remnants of the terror group," Encinas said.

The military said the BIFF has about 200 to 300 members, mostly disgruntled former members of the larger insurgent group Moro Islamic Liberation Front, who signed a peace agreement with the government in 2014.

The BIFF is among the several groups in Mindanao that pledged allegiance with the Islamic State of Iraq and Syria a few years ago.