Some United Airlines flights across the United States, from New York to San Francisco, were delayed Saturday due to a technological glitch.

United Airlines passengers said on social media that the issue affected operations at several major airports, including Washington Dulles International Airport in Virginia and Newark Liberty International Airport in New Jersey. Some passengers said they experienced delays, while others said they had problems checking in, boarding and checking their bags.

Down Detector, a site that tracks status updates and outages, showed that passengers began reporting the problems before 7:40 a.m. Saturday. As of 8:23 a.m., Down Detector had recorded more than 430 reports.

A United Airlines spokesperson said the issue has now been resolved.

“Our teams are getting our operations back to normal after a technology outage impacted contact centers and registration processes today,” the spokesperson told Business Insider. “We encourage customers to check their flight status in the United app as they prepare to travel today.”

The spokesperson said the outage affected the airline’s reservation system. As a result, the company was unable to process customer records and tickets. The spokesperson said the disruption did not affect flights that were already in the air or had left the gate.

United Airlines was one of several airlines that faced major disruptions after widespread technology outages related to a CrowdStrike update two years ago. At the time, the airline warned pilots that they may not be able to contact ground services. As a result, it was forced to cancel thousands of flights.