UPDATE: Computer Glitch Solved, United Airlines Gets Back to Flying

Thousands of passengers were stranded at San Francisco International Airport Friday night - and many more at airports nationwide - because of a United Airlines computer glitch that, among other problems, prevented the airline from checking baggage.

According to the website FlightStats, twelve flights scheduled to depart SFO after 6pm Friday night were cancelled, including two international flights to Frankfurt and London, and flights to New York, Newark, Las Vegas, Denver, Portland, Eugene and Santa Ana.

There were no outbound flight cancellations from Oakland International Airport, and one flight was cancelled at San Jose's Mineta International.

Four inbound flights to SFO between 6pm and midnight were cancelled.

This Saturday morning, United has cancelled four flights flying between midnight and noon today out of SFO. A 6 a.m. flight to Phoenix, and later flights to Missoula, Los Angeles and Santa Ana have been cancelled. No flights out of San Jose or Oakland are affected.

United is warning delayed customers it may take some travelers several days to get to their destinations since many of its daily flights are fully booked, allowing for only a few seats to be used in subsequent days.

On the United Airlines website, the airline states:

"The airline experienced a network connectivity issue at about 7:15 p.m. CT which was resolved through troubleshooting procedures and restored at midnight. The airline has issued a waiver policy permitting customers on affected flights to cancel or rebook their itineraries without penalty. 

United apologizes for the disruption caused to travelers at affected airports and is re-accommodating travelers where necessary. 

If you traveled on Friday, June 17, and arrived without your bags, or if your bags traveled ahead to your destination and you did not, please call United Baggage Services at 1-800-221-6903. Please note that due to high call volumes, you may experience longer than usual wait times.

Customers traveling on June 18 are advised to check in online and print boarding documents before arriving at the airport. Please plan to arrive at the airport early, and if you’re not checking bags, proceed directly to the security checkpoint and to your assigned gate."

Lines Friday night to gain information at the airline's counter were several hundred people deep at SFO, according to Bryan Carmody, a communications director for United Service Organization of Northern California.

Part of the problem, Carmody said, was that passengers could not  pass through airport security with anything larger than carry-on luggage and  personal items.