Thousands of flights delayed as Southwest glitch grounds planes

Thousands of flights have been delayed in the United States after Southwest Airlines was forced to temporarily ground all flights because of a "technical glitch".

The airline said it would work to accommodate passengers disrupted by the one-hour nationwide stoppage.

Flight Aware says over 5,400 flights were delayed into our out of the US on Tuesday. More than 100 were cancelled.

It's the latest setback for the budget airline.

"This morning Southwest Airlines experienced a technical issue with one of their internal systems," the FAA said.

It added that all departures had been paused at the airline's request while the Dallas-based carrier addressed the issue.

"The pause has been lifted and their service has resumed," the FAA said.

On social media, representatives for the airline asked passengers to message them directly for assistance and sought to reassure passengers that the company was working to resolve the issue.

Southwest Airlines has been under fire after "staff shortages" during the Christmas holiday season led to 16,700 flight cancellations and disrupted travel plans for two million customers.

At the time, the US Department of Transportation said it would investigate whether customers were subject to "unfair and deceptive" practices.