United Airlines said its system is back up and running after passengers in several cities said they experienced a massive computer outage, which stranded them at airports across the country.
Daniel Acker | Bloomberg | Getty Images
This is at least the third major computer outage for the Chicago-based airline since June.
"Our system is up. We're resuming operations for affected flights," United said in a statement.
(Read more: United Suffers Computer Issues in August)
Passengers were being told by pilots and airport agents that computers were down. Some fliers had been waiting nearly two hours to depart.
The Associated Press contributed to this report.