"At approximately 8 p.m. Pacific on Sunday, Alaska Airlines experienced an IT outage that’s impacting our operations. We requested a temporary, system-wide ground stop for Alaska and Horizon Air flights until the issue is resolved," the airline said in a statement Sunday evening. The airline said it resumed operations at about 11 p.m. PT.

Alaska Airlines grounded all its flights due to an undisclosed technical error affecting its entire system, the carrier announced early Monday.

“We apologize to our guests for this inconvenience. There will be residual impacts to our operation throughout the evening,” it said in its statement.