A passenger on a flight told police he opened a door on the plane minutes before it landed in South Korea on Friday because he was "uncomfortable", according to reports.
The man, in his thirties, told police that he opened the door because he "wanted to get off the plane quickly", Yonhap News Agency said. He also told police he was stressed after losing his job recently.
The man opened the door when the plane was about 213 metres above the ground, causing panic onboard.
Nine passengers were sent to the hospital with breathing issues. All were dismissed from the hospital after about two hours, an official said.
Police plan to arrest the detained man after investigations end, Yonhap said.
A former Korean Air cabin safety official said that as far has he knew, this case was unprecedented, but that passengers have opened emergency exits without authorisation while the plane is on the ground.
A South Korean transport ministry official said on Friday that it was possible to open emergency exits at or near ground level because the pressures inside and outside the cabin were similar.
