US carrier Alaska Airlines said it had grounded flights at all airports due to an unspecified technology outage affecting its operations.

The ground stop on Thursday night also applies to its subsidiary Horizon Air, a Federal Aviation Administration advisory showed.

The ground stop was requested for a period of more than two hours, according to the advisory. The airline also briefly grounded all of its flights in July for about three hours due to an IT outage.

"Alaska Airlines is experiencing an IT outage affecting operations. A temporary ground stop is in place. We apologize for the inconvenience," Alaska Airlines said in a statement issued on social media.

The airline was also responding on social media to customers who were posting concerns and complaints online.

"Unfortunately, we are experiencing an error on our system, but our IT team is working to get this resolved as soon as possible," it said, in response to an X user who asked if the airline's app was also having issues.

It issued a similar response to a user who asked about booking problems on the airline's website. (Reuters)