Rescue teams shifted the injured to Civil Hospital.
Dawn quoted SP Sariab Akhlaqullah Tarar as saying that the blast was caused by an improvised explosive device (IED) planted at the side of the road.
The provincial government's spokesman strongly condemned the blast on Twitter.
"Police and other security agencies have surrounded the area. Directions have been issued to the hospital administration to take care of the injured," he tweeted.
More to follow