A flight from New York to Phoenix was diverted to Missouri on Wednesday after three passengers on board behaved in a "suspicious" manner.
The three passengers were taken off the US Airways flight after it landed in St Louis, Missouri where the police took them in, the Transportation Security Administration said.
"US Airways Flight 457 from John F Kennedy International Airport to Phoenix Sky Harbor International Airport diverted to Lambert -- St Louis International Airport at the request of the flight crew, due to suspicious behaviour exhibited by three passengers," the TSA said in a statement.
The plane was swept and cleared for flight, it added.
The incident comes a couple of days after F-16 fighter jets were scrambled to escort two US flights after their crew were unnerved by two of its passengers spending a long time in the plane's lavatory on September 11.
The planes landed without incident in Detroit and New York and the six passengers who exhibited "suspicious behaviour" were released without charge after being questioned.