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.

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,

Concerns have been raised about the safety risk of bringing portable batteries in carry-on luggage for flights, as a lithium-ion battery is suspected as the cause of the fire that destroyed Air Busan’s passenger plane on Tuesday night.