According to local officials, the incident took place late on Monday in the vicinity of Satellite Town area of the city.
A senior security official Razzaq Cheema said the explosion targeted a police vehicle which was carrying security personnel to protect a mosque.
Cheema further added that the four personnel of Rapid Response Group were killed in the explosion and 12 others were wounded.
According to Cheema, the explosives were planted in a motorcycle which was detonated when the police vehicle arrived in the area.
According to reports, the Tehrik-e-Taliban Pakistan has claimed responsibility for the attack.
Last night’s incident took place days after a group of militants stormed a five-star hotel in Gwadar port of Pakistan leaving at least five dead.