The incident took place when security forces responded to a blockade of a major highway by militants in the southwestern Baluchistan province.
Several "terrorists" were also injured during the operation, the sources told Anadolu Agency.
The incident – the latest in a string of renewed "terror" attacks in recent months – came a day after nine policemen were killed in a clash with "terrorists" in the Ziarat district.
Baluchistan, a mineral-rich region and a key route for the multibillion-dollar China-Pakistan Economic Corridor, has long been plagued by separatist militancy.