The militants linked to the banned Balochistan Liberation Army (BLA) were killed in Sibi district of the province.
Balochistan government spokesman Anwar-ul-Haq Kakar said those killed included Aslam Acho, alias Meerak Baloch, second- in-command of the BLA.
"He was among those killed when security forces carried out a raid on an intelligence tip-off," Kakar said, adding that the commander carried a head-money of Rs six million.
"He was also a spokesman for the proscribed outfit."