An American Airlines plane that made an unscheduled stop Thursday morning in St. Louis because of an unspecified "security issue" has been cleared to continue its journey from Ohio to Arizona, airport officials said.

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Flight 534, headed to Phoenix from Columbus, Ohio, was diverted to Lambert-St. Louis International Airport around 8:15 a.m. CST due to an unspecified "security issue," according to multiple reports. Officails said at 10:30 a.m. that a security sweep of the plane turned up no evidence of a credible threat.

A spokeswoman for the FBI's St. Louis Division told WCMH that "some kind of threat" led to the stop, although she did not elaborate. The St. Louis Post-Dispatch reported that bomb-sniffing dogs were searching the plane.

Airport operations were not affected, officials at Lambert–St. Louis International Airport said.

Pilots asked to land in St. Louis and for "a security check of the aircraft," Jeff Lea, a spokesman for the airport, told the St. Louis Post-Dispatch. He did not elaborate on what prompted the check.

The plane had five crew members and 113 passengers on board.