WASHINGTON -- Alaska Airlines said Monday it had resumed operations after hours earlier requesting its fleet be grounded because of an "IT outage."

The airline apologized for the disruption, and urged travelers to check their flight status before heading to the airport -- adding it "will take some time to get our overall operations back to normal".

The airline earlier told AFP it "experienced an IT outage that's impacting our operations" and that it had "requested a temporary, system-wide ground stop for Alaska and Horizon Air flights until the issue is resolved."

Before the grounding was lifted, the US Federal Aviation Administration (FAA) status page showed all destinations affected by the halt of Alaska's mainline aircraft.

"We apologize for the inconvenience," Alaska Airlines said in a statement.

"As we reposition our aircraft and crews, there will most likely be residual impacts to our flights."

In a separate statement posted on X, the airline said it has "resolved its earlier IT outage", without giving details.

The grounding drew a backlash from frustrated passengers.

"This is brutal. We've been sitting at the airport for two hours," wrote an X user named Caleb Heimlich in one of such replies.

"It's 10:20 pm, people are tired, hungry, etc. This is not okay," said another.

Alaska last year also experienced an IT outage that caused significant disruption to its operations, including delayed flights.

At the time, multiple users complained they were facing difficulties accessing its app and website.

AFP