According to reports, security forces launched the operation in the district on Thursday morning after receiving the intelligence reports about the presence of terrorists of a banned outfit, Xinhua news agency reported.
Forces also claimed to have confiscated a huge cache of explosives and weapons from the possession of the killed militants.
At least nine most wanted terrorists of a banned militant organization were also among the killed.
Security forces also destroyed two hideouts of the militants in the area.
More than 400 personnel of the Frontier Corps, a paramilitary force, along with intelligence personnel backed by the helicopters have been conducting the operation in two different districts of Kalat and Mustung of the country’s southwestern province of Balochistan.
On Friday, the security officials said they killed 13 militants and arrested one dozen during the operation.
All the killed militants were involved in attacks at the security forces and in other heinous activities across the country.