Shares of Air Busan dropped on Friday, after a plane belonging to the budget carrier caught fire earlier this week.

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.

The fire broke out in the back of the cabin, officials said. All 176 people on board, including passengers and crew members, were evacuated, some with minor injuries.