Delta Air Lines says it has grounded flights as it works to address a “technology issue.”

The airline said in a statement Tuesday evening that Delta IT teams were working to fix the issue, which affected “some” of its systems. The statement does not specify what the technology issue is.

It was not immediately known how many people or flights have been affected.

Our teams have restored all IT systems after a technology issue briefly affected some of our systems this evening. All groundstops have been lifted. https://t.co/02Y7MHwi06

— Delta (@Delta) September 26, 2018

(AP)