United Airlines cancelled flights in the US on Friday night after a systems breakdown affected its website, flight departures and reservations operations.
Although the five-hour outage was solved at around 1 a.m. U.S. Eastern Time on Saturday, the airline expects logistical problems to linger for the rest of the weekend.
United Airlines blamed the incident on a "network connectivity issue" that hit the affected systems at around 8:15 p.m.
"While we will be experiencing some residual effect on our flight operations throughout the weekend, United is committed to restoring normal operations as soon as possible. We encourage customers to print their boarding pass prior to arrival at the airport and give themselves extra time," Alexandria Marren, the airline's senior vice president of System Operations Control, said in a statement.
United Airlines cancelled 16 flights on Friday night and at least 15 more on Saturday, impacting thousands of travelers, The Wall Street Journal reported.
United Airlines is part of United Continental Holdings, which also owns Continental Airlines. That other airline wasn't affected by the problem.