Alaska Airlines said its operations have resumed after a temporary ground stop was issued on all its flights and those of a regional subsidiary Horizon Air due to an IT outage affecting its operations,

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.

All Alaska Airlines and Horizon Air flights are affected by the ground stop, which the company has blamed on an IT outage.