Alaska Airlines has resumed operations following an undisclosed technical error affecting its entire system for approximately three hours.

Alaska Airlines said it has requested a ground stop for its fleet as well as for that of regional subsidiary Horizon Air amid a computer system outage Sunday night. The request to federal authorities would keep Alaska and Horizon flights out of the air until the system is returned to normal operations, Alaska said in a statement.

Alaska Airlines grounds its flights and those of a regional subsidiary Horizon Air due to an IT outage affecting its operations, the company said Sunday evening.