According to media reports, the bomb exploded at Sibbi Phattak near police vehicle.
Minutes after the blast in Quetta, two security personnel were killed in an IED explosion in the Frontier Region (FR) of Bannu in the country's northwest.
Pakistan has faced many attacks on security forces since the start of Operation Zarb-e-Azb and then Operation Raddul Fasaad, particularly Balochistan and FATA.
Balochistan Home Minister Sarfaraz Bugti while condemning the attack confirmed that six policemen had lost their lives in the attack while 22 others were injured and being treated at the Civil Hospital and Combined Military Hospital (CMH) in Quetta.
"These cowardly attacks can not shake our unflinching national resolve against terrorism and extremism", the prime minister said in a statement.
Mr. Sarfraz Bugti said that Pakistan will take the war against terrorists and their facilitators to their ultimate conclusion.More news: Crazy Justice: cross-play PC, Nintendo Switch, Xbox One
The group of elite police were targeted on the Sariab road in the outskirts of Quetta, capital of Balochistan province, as they headed to work.
He added: "These cowardly attacks will not hinder our security forces in executing their duties".
Abdul Salam was shot multiple times, police said. At least 12, including nine policemen, were also injured in the attack, according to police sources.
He said that the injured have been shifted to hospitals for medical treatment.
Security forces have cordoned off the area while BDS personnel are collecting evidence to ascertain exact nature of the blast.
Both Prime Minister Shahid Khaqan Abbasi and President Mamnoon Hussain condemned the blast and expressed grief and sorrow over the loss of precious lives in the attack.