Thousands of flyers were stranded Friday, June 17 night in airports across the country when United Airlines computers crashed, interrupting departures and reservations and disrupting the airline's website.

The airline confirmed the problem on Twitter. United spokesman Charles Hobart said the computer problems started at about 7:15 p.m. He did not elaborate on the nature of the problem. As a result of the outage, long lines of passengers formed at check-in counters at Chicago's O'Hare International and Denver International airports, two of United's largest hubs.

Hobart said the airline is apologizing to travelers affected and is seeking to resume operations as quickly as possible, AP reported.

United is the second airline to have its operations disrupted by computer problems this month. Last week, a power outage grounded or delayed U.S. Airways flights nationwide. Passengers couldn't make reservations, check in online, change their flights or check flight status.