KARACHI - A couple and their child suffered burn injuries due to an explosion triggered by a gas leakage at their house in Jauharabad Block 14 in Karachi on early Friday morning. Rescue officials said the explosion occurred due to gas leakage from the cylinder and engulfed the entire house, a private news channel reported. The ambulance and a fire tender reached the spot and extinguished the fire. The injured were shifted to the nearby hospital, sources said, adding that the police had started investigation.