The firing also injured his cousin Nauman Baig.
According to police, Mirza Zafar Baig was sitting outside his house when three men on motorcycle opened fire on him as a result of which he and his brother died on the spot.
The injured cousin was shifted to Allama Iqbal Memorial hospital for medical assistance.
Heavy contingent of police reached the scene on getting information of the incident.
Lawyers and JI workers protested against the killings and demanded immediate arrest of the culprits.
District Bar Association has announced day of mourning and court boycott against the incident. Police say that the event seems to be the result of personal enmity.