The incident occurred around 7:33am in Doghabad area of PD7 of the city, after a mine exploded.

The bomb was placed on a vehicle carrying doctors working at Pul-e-Charkhi prison, a police statement said.

The victims are yet to be identified.

"Before this, officials at Istiqlal hospital confirmed that at least three people were killed and two were wounded in the blast and the dead and wounded have been transferred to the hospital," local Tolo News reported. 

No group, including the Taliban, has claimed responsibility for the blast so far.