Harriet Baskas

Special for USA TODAY

Airlines, airports and travelers around the country are working to recover from a Monday evening computer glitch that shut down U.S. Customs and Border Protection processing systems at numerous airports for several hours.

The outage began about 5 p.m. EST and caused long lines, missed flights and delays for thousands of travelers arriving in the U.S. at airports that included Miami, Fort Lauderdale, Boston, New York, Atlanta, Chicago, Los Angeles and Houston.

During the outage, arrivals were processed manually and Customs officers “had access to national security-related databases and all travelers were screened according to security standards," CBP said in a statement.

When the computer systems were fully restored at about 9 p.m., CBP reported that there was “No indication the disruption was malicious in nature,” although a reason for the massive computer outage was not immediately cited.

To accommodate the hundreds of passengers stranded at Miami International Airport Monday night because of missed connections, the Miami-Dade Aviation Department opened its auditorium area for passengers to spend the night there, said airport spokesman Greg Chin.

"We did have passengers at many of our hubs — including MIA — that missed their connections due to delays during U.S. Customs and Border Protection processing," said American Airlines spokesman Ross Feinstein. "Our teams worked to book passengers on the next available flight, including flights this morning to their final destinations."

During what CBP referred to as a “technology disruption,” travelers took to Facebook, Twitter and other social media platforms to express their frustration and displeasure at being made to wait in long lines, especially after the long holiday weekend.

"What happened at Customs airport checkpoints yesterday is disturbing, but unfortunately it is not surprising," said Roger Dow, U.S. Travel Association president and CEO. "Technology at these facilities is too outdated to cope with existing travel volume, let alone the increased traffic we hope and expect to see at our gateway airports in years to come."

Harriet Baskas is a Seattle-based airports and aviation writer and USA TODAY Travel's "At the Airport" columnist. She occasionally contributes to Ben Mutzabaugh's Today in the Sky blog. Follow her at twitter.com/hbaskas.