Three levies personnel were martyred in Quetta's Sariab area on Friday, the police confirmed.
Unknown assailants opened fire on a vehicle carrying the levies personnel in the city's Killi Bangulzai vicinity.
The bodies were shifted to the city's Civil Hospital.
Security forces reached the site of the incident soon after it was reported and cordoned off the area.
Investigations into the incident are under way.
Last month, two policemen were killed in a shooting by unknown armed assailants in Balochistan's provincial capital. The incident occurred on Sarki Road when the attackers opened fire on the on-duty policemen. Four passersby were also injured in the attack.
Two assailants were killed as a result of the retaliatory firing by law enforcement personnel from a nearby police mobile. One of the injured attackers, however, had managed to get flee.