A passenger opened the door of a South Korean plane shortly before it landed, officials said.
Some people on the Asiana Airlines flight tried to prevent the person from opening the door, but it was eventually partially opened, the transportation ministry said.
The plane, with 194 people on board, was heading for the southeast city of Daegu from the southern island of Jeju.
The flight normally takes about an hour.
It was not revealed how long the door was open.
The flight then landed safely at Daegu International Airport.
The incident terrified some passengers but no one was injured, although some passengers were assessed at a hospital, Asiana and government officials said.
The person who opened the door arrested
The Transportation Department later said the person who opened the door had been arrested.
Footage showed plainclothes officers arresting a passenger.
The ministry said police arrested the passenger and are investigating a possible violation of aviation security laws.
Their motive was not known.
The passengers included teenage athletes who plan to attend athletic competitions in Ulsan, another city in the southeast.