Thousands of travelers at U.S. airports faced delays late on Friday because of an outage of U.S. Customs and Border Protection's (CBP) processing systems, officials said.

CBP said in a statement the outage was temporary and "officers continue to process international travelers using alternative procedures until systems are back online. Travelers at some ports of entry are experiencing longer than usual wait times."

People at various U.S. airports posted videos on social media sites of lengthy lines at processing checkpoints and several airports warned of extensive delays.