Senior police officer Malik Nisar said the assailants opened fire on a pick-up truck carrying a group of Hazara Muslims in the provincial capital, Quetta, killing five of them on the spot.
The attackers fled the scene and are now at large, according to the official.
Local police Chief Hidayat Ullah said two other passers-by were also wounded in the attack.
No group or individual has so far claimed responsibility, but Shia Muslims of the Hazara community frequently come under attack by Taliban-affiliated, ISIS and other militant groups active in Balochistan.
Last week, the Takfiri ISIS terror group carried out a bomb attack against a Shia shrine in a remote Balochistan village, leaving two dozen people dead. A similar assault on the same shrine had killed 35 people back in 2005.
The violence against Shia Muslims has claimed thousands of lives in the country over the past decade.
Pakistan security forces have been engaged in operations against the terrorists in Balochistan Province.
Elsewhere, an official said at least three soldiers were shot dead by gunmen, who attacked their vehicle in the tribal region of North Waziristan. Eight soldiers were also wounded in the incident.
North Waziristan was a stronghold of the Taliban militant group until 2014, when Pakistan’s military launched a major offensive and pushed many of its militants across the border into Afghanistan.
