Officials said there were 76 passengers on an American Airlines flight 1671 from Cancun to John F. Kennedy International Airport in New York.
When the flight arrived, 13 passengers were ushered through the wrong exit.
"Due to an airline error, 13 of the 76 passengers inadvertently exited through a domestic gate before being processed by CBP," Customs and Border Protection said in a statement.
Ten people have since returned for processing, but three U.S. citizens still need to be screened.
More Details: NBC NEWS
