Karachi: Four people were injured in a bomb attack on a vehicle of a local trader at Ittehad Town in Karachi on Sunday. Police and rescue sources said suspect extortionists targeted the car of a contractor Muhammad Din Afridi with a remote controlled explosive devise planted in a motorcycle. As a result, the guard and a nephew of the contractor and two other people were injured who were rushed to hospital. The car of the contractor, a taxi and an ambulance car were damaged in the attack. Police reached the area and began probe.