NORTH TEXAS (CBSDFW.COM) — Fort Worth-based American Airlines was among the carriers experiencing problems with check-in, causing long lines at Dallas Fort Worth International and Love Field Airport.

A computer outage with Sabre, the company that some airlines use for flight bookings, caused issues with check-in and boarding systems for American, JetBlue and Alaska Airlines.

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When a customer complained on Twitter American Airlines responded saying, “Our teams are engaged and working to fix this ASAP. We appreciate your patience and apologize for the wait.”

“Earlier today, Sabre had a technical issue that impacted multiple carriers,” American Airlines said in a statement. “This issue has been resolved and our systems are back online. We apologize to our customers for the inconvenience.”

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The problem has been resolved, but flight delays are being reported nationwide. Travelers are being advised to check their flight status before heading to the airport. Staff