A Southwest Airlines flight from Chicago is under investigation after it landed at the wrong airport seven miles from its intended destination.

Flight 4013, carrying 124 passengers and five crew members, was scheduled to fly from Chicago's Midway International Airport to Branson Airport, Missouri.

But the Boeing 737-700 landed at Taney County Airport instead, on a runway half the size of its proper destination.

It was unclear why the flight went to the wrong airport. Federal Aviation Administration (FAA) spokesman Tony Molinaro said an investigation has been launched.

Airline spokesman Brad Hawkins said "The landing was uneventful, and all customers and crew are safe. Our ground crew from the Branson airport arrived at the airport to take care of our customers and their baggage".

Flight 4013 had been scheduled to go from Branson to Love Field in Dallas. Mr. Hawkins said another aircraft was flown into Branson at 10pm on Sunday to take the passengers and crew to Dallas.

The runway at Taney County, also known as M. Graham Clark Airport, is 3,738ft. Branson Airport's website says its runway is 7,140ft long.

The Southwest plane is able to take off from Taney County and the company said it expected it to fly out "as early as tomorrow (Monday) morning".

It is the second time in two months that an aircraft has landed at the wrong airport.

In November, a Boeing 747 Dreamlifter which was supposed to deliver parts to McConnell Air Force Base in Wichita, Kansas, landed nine miles north at Colonel James Jabara Airport.