At least 20 people including six children and women were injured in the blast in Mehmoodabad area on Thursday.
The blast took place near Sitara Bakery in Mehmoodabad No 6 wherein 20 people injured. The blast, which was heard in the radius of several kilometers, spread fear among local residents. Nearby shops and vehicles were also damaged in the incident.
The scheduled rally of the Pakistan Muslim League Nawaz (PML-N) candidate was apparently the target of the blast, official sources added.
Exact nature of the blast is yet to be ascertained, however, a completely destroyed suspected motorcycle was found from the site. Most of the injured were shifted to Jinnah Postgraduate Medical Centre while the rest were moved to a nearby hospital.
The city police have said an explosive device was planted in plot.