A Qantas airliner was forced to make an emergency landing at a New Zealand military base on Saturday, leaving passengers stranded in a sweltering cabin for four hours as emergency work was carried out on the plane.

The Boeing 737 jet was travelling from Melbourne to Wellington when it developed a mechanical issue and the pilots decided to land at Ohakea military base, 150 kilometres north of Wellington.

The plane was unable to land flight QF171 at nearby Palmerston North airport due to local weather conditions.

Passengers on-board were not allowed to leave the aircraft as customs officials made the two-hour trip from Wellington.

A woman whose partner was aboard the plane told the Sydney Morning Herald the aircraft apparently had a problem with its the “wing flaps”.

“They couldn’t get them to work,” she was quoted as saying.

Posts on social media indicate the passengers waited four hours on the plane before eventually being taken by bus to their destination.

One passenger, Ryan Newington, tweeted that it was “extremely hot” in the plane and said there had been “shocking communication” from the airline during the wait.

#QF171 sitting on the tarmac in the sun, getting extremely hot in the plane. Many passengers visibly distressed. @Qantas won't open the door because reasons. Customs apparently driving up from Wellington (2 hours away), not sure theres much point, we'll all be roasted by then.

— Ryan Newington (MVP) (@RyanLNewington) November 16, 2019

Mr Newington told TV New Zealand that the pilot informed passengers the plane was diverted due to a wing flap being stuck.

Another passenger tweeted it was a “difficult problem to solve”.

“Can’t leave plane because no customs, can’t fly plane as broken, can’t get replacement plane (easily at least) as at air base,” she wrote on Twitter.

Everyone is through 'customs', yet for some reason we are not yet allowed to get on the buses. Lots of talk about food (lack of), since breakfast was the last meal. At least 2 hour drive to Wellington from the time we can get on. Shocking communication from @qantas #qf171 pic.twitter.com/WdJnzuJlWN

— Ryan Newington (MVP) (@RyanLNewington) November 16, 2019

Qantas issued an apology to pasengers for the inconvenience caused.

(Editor’s note: Thanks to the many readers who noted the original illustration was not a 737. The wrongly archived photo has been replaced.)