A retired army officer was gunned down by unidentified assailants in Karachi on Wednesday.

According to police sources, retired colonel Tahir Zia was in a car near the Baloch Colony bridge when two assailants on a motorbike rode up to his vehicle and shot at him with a 9mm pistol.

Zia was killed in the gun attack, while a passerby was injured by stray bullets, the sources said.

Superintendent Police Gulshan Dr Fahad Ahmed said the attack appeared to be a target killing.

The police is conducting an investigation into the attack.