The attack occurred amid ongoing counterterrorism operations in the province, including Operation Shaban. Pakistani security forces have claimed that 109 terrorists have been killed in operations since July 5.
Deputy Commissioner Abdul Majeed Sarparah told Dawn: "The incident took place in Mashkail town close to the Pakistan-Iran border area, when armed men riding motorcycles opened fire on shops where the labourers from Punjab were working."
Police officials said the five workers suffered multiple bullet injuries and died at the scene.
The attackers fled following the shooting, officials said.
Police and other security personnel rushed to the site after receiving information about the attack and shifted the bodies to a government health facility in Mashkail, Dawn reported.
Security forces subsequently launched an operation in the area to track down those responsible for the attack.
Balochistan has witnessed several attacks targeting labourers from Punjab in recent years.
In March last year, four labourers from Punjab were shot dead by unidentified assailants in Balochistan's Kalat district.