According to the sources, The three lawyers were gunned down while on the way to city court.
The deceased were identified as advocate Shakeel, Badar Munir and Kafil Ahmed. While the injured lawyer was shifted to civil hospital.
The attackers were riding motorcycles and chased the lawyers from the city courts, police said.
Police describes the incident as target killing.
The lawyers of Sindh Bar council announced court boycott and strike on Thursday.