South Korean officials are launching an investigation into the cause of the fire that engulfed an Air Busan passenger plane while awaiting takeoff at Busan's Gimhae International Airport, with some eyewitness accounts leading to speculation that a portable power bank may have caused the blaze.

It is a month since the deadliest air disaster on South Korean soil when a Jeju Air plane coming from Bangkok crashed on Muan Airport's runway as it made an emergency belly landing, killing all but two of the 181 people and crew members on board.

Shares of Air Busan dropped on Friday, after a plane belonging to the budget carrier caught fire earlier this week. Air Busan shares traded down 3.8% as of 0018 GMT, after falling as much as 6.1% to 2,