Computer problems delay United flights nationwide

United Airlines computer system delays

An unspecified problem with its passenger computer system delayed United Airlines flights across the country on Tuesday, compounding existing weather-related woes.

"This morning we experienced intermittent issues with our passenger service computer system, causing some flight delays. With the system now restored, we are working to get our customers to their destinations as soon as possible. We apologize for any inconvenience," United said in an updated statement Tuesday afternoon.

Social media lit up Tuesday morning with complaints from passengers stranded at various airports. The Chicago Sun-Times reported delays in Chicago, Denver, Los Angeles and Washington, among other places.

United's Twitter staff responded to most complaints with "We're experiencing intermittent system-wide issues." Further details were not immediately available.

(Read more: More winter travel woes)

Flight tracking site FlightAware reported that 27 percent of United's flights, nearly 600 in total, were delayed as of mid-afternoon. The total number of delays across all airlines was elevated, though, due to weather issues in the midwest and northeast.