After making an emergency landing in Kazakhstan, a Boeing 777 got stuck in the mud. Over 300 passengers then waited 20 hours to be rescued by another airline.

• A Swiss International Air Lines flight diverted to Kazakhstan due to a medical emergency.
• The Boeing 777 came off the runway in Astana and got stuck, leaving over 300 passengers stranded.

Over 300 airline passengers have been rescued after spending an unexpected day in Kazakhstan.

Saturday's Swiss International Air Lines flight from Tokyo to Zurich changed course about halfway through the 14-hour journey, according to data from Flightradar24.

An airline spokesperson said this was due to a medical incident on board.

They added that, after landing in Astana, the Kazakh capital, "the passenger concerned was handed over to medical personnel on site."

However, the Boeing 777 ran into difficulty as it prepared to take off again.

The taxiway at Astana Airport was closed, meaning the pilots had to try to turn the plane around while still on the runway, the airline spokesperson said.

However, the maneuver was unsuccessful, with the plane's landing gear becoming stuck in the grass.

The Boeing 777 was towed back onto the runway, and the airline considered how to get the passengers back on course.

"As rebooking options in Astana are limited, the possibility of sending a new aircraft and crew from Zurich is also being examined," the airline said on Saturday.

Ultimately, its sister company, Austrian Airlines, stepped in to help. Both carriers are part of the Lufthansa group.

An Austrian Boeing 777 flew from Vienna to Astana on Saturday night before returning the following day — taking off 20 hours after the first plane landed in Kazakhstan. The Swiss spokesperson said there were 331 people on board.

Swiss then dispatched another 777 to transport passengers from Vienna to Zurich — about 370 miles.

"We thank all our passengers for their understanding and patience in this exceptional and unforeseen situation," the airline said.

"We apologize once again for any inconvenience caused," it added. "A big thank you also goes to all the employees involved for their tireless and outstanding efforts."