Many casualties are feared after a plane carrying more than 100 passengers and crew crashed into houses shortly after the pilot reportedly notified air traffic control of a technical fault.
The Pakistan International Airlines jet was on its final approach to Karachi Airport when it went down in a residential area near Model Colony and disappeared from radar.
A number of houses were damaged or destroyed and a major rescue operation was underway to save any survivors.
A civil aviation authority spokesperson told local media that 99 passengers and eight crew members were on board the Airbus A320.
Pictures and video show a huge cloud of black smoke billowing into the air following the crash, which happened at about 2.45pm local time on Friday.
Flight PK8303 was on a domestic journey from Lahore.
Civil Aviation Authority (CAA) sources said the captain reported a technical fault and the planbe disappeared from radar shortly before it was due to land at Karachi’s airport, 24 News reported.