Dozens of gunmen were involved in the attack in the restive Baluchistan province. A separatist group has claimed responsibility.
Gunmen ambushed a passenger bus in southwest Pakistan on Thursday, killing 14 people. A local official said it was unclear who was behind the shooting.
The men reportedly entered the bus, demanded to see everyone's IDs, and then commenced their attack on specific passengers. It remains unknown what ethnicity or denomination the assailants were marking.
Pakistan Prime Minister Imran Khan condemned the attack as "an act of terror," and ordered authorities "to make every possible effort to identify and to bring the perpetrators of the barbaric act to justice."
Baloch separatists claimed responsibility for the attack later on Thursday. The insurgents seek Baluchistan's "independence" from Islamabad and are known to target the security services and people from Punjab, as they tend to make up the bulk of soldiers stationed in Baluchistan.
The separatists claim that the government does not evenly distribute the region's resources. There are also Islamist extremists active in the area, who have launched attacks on minority Shiite Muslims in the past.