Pakistan’s prime minister, Imran Khan, has expressed shock after an aircraft operated by flag-carrier Pakistan International Airlines crashed in a built-up area of Karachi.

Khan says that PIA chief Arshad Malik is heading for the city following the accident involving an Airbus A320 arriving from Lahore.

“[An] immediate inquiry will be instituted,” says Khan.

Television station Geo News reports that the flight involved is PK8303 and that aircraft came down in a populated area.

It adds that 98 occupants were on board, comprising 91 passengers and seven crew members.

Social media images show a chaotic scene with extensive damage to several buildings, black smoke, and rescue vehicles working their way through crowds on the streets.

Pakistan Army Aviation Corps helicopters have been despatched for “damage assessment and rescue efforts”, according to the Pakistan armed forces spokesman, along with urban search teams.

The spokesman says troops and civil administration personnel have reached the area for relief work.

Circumstances of the accident are unclear. Meteorological data from Karachi airport indicate good visibility and no adverse weather conditions.