UPDATED 01/30/16 12:03 a.m.
NEW YORK (CBSNewYork/AP) -- Delta Air Lines grounded its domestic flights for hours late Sunday due to what was described as "automation issues."
The the Federal Aviation Administration and the Port Authority of New York and New Jersey advised the public of the outage around 8 p.m. Sunday.
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Delta said in a statement that the delays only affected flights on the ground.
"Delta teams are expeditiously working to fix a systems outage that has resulted in departure delays for flights on the ground," the airline said. "Flights in the air remain unaffected. Delta apologizes to customers for the inconvenience."
International flights were also unaffected.
The Delta website and app were also down for a period of time late Sunday, the airline confirmed via Twitter.
KLM and Virgin America airlines were also affected, the Port Authority said.
As CBS2's Erin Logan reported, all was calm at Newark Liberty International Airport late Sunday, and no passengers who spoke to CBS2 said they had been affected.
But annoyed passengers did take to Twitter, and Delta apologized for any inconvenience.
Shortly after midnight Monday morning, Delta reported that operations were "returning back to normal" and advised passengers to check back on flight times.
About 150 flights were canceled Sunday night with more expected, Delta said. Not all delays and cancellations were reflected on Delta's systems.
Sources told CBS News' Kris Van Cleave the Aircraft Communications Addressing and Reporting System (ACARS) for United went down on Sunday of last week. The system records and transmits information that pilots need to know in order to safely take off.
Delta told investors the glitch cost the airline more than $150 million.
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