Four persons were injured when firing occurred near Empress Market Saddar.
The firing incident took place when a procession of Yaum Ali (RA) was passing off Empress Market in Saddar.
The injured were shifted to a nearby hospital.
The incident was followed by aerial firing by unknown men from an old building in Saddar market.
CCPO Wasim Ahmed said that police and Rangers have surrounded the building and trying to carry out a search by entering into it.