CNN reports that three Orthodox Jewish businessmen praying on an Alaska Airlines flight from Mexico City to Los Angeles on Sunday triggered a security alert. Passengers became alarmed when the three began praying out loud "in a language other than Spanish" shortly after takeoff. Flight attendants said the men appeared to have something strapped under their clothing as well-- presumably tefellin which observant Jews wear during week day morning prayers. Flight attendants alerted the flight deck which in turn alerted security at LAX. Airport police, the FBI and agents from Customs and Border Protection all met the men when the flight landed. After questioning and a search of their baggage the men-- all cooperative with authorities-- were cleared to go.
UPDATE: CNN (3/15) reports that Alaska Airlines has apologized for the handling of the incident. However the airline explained that the flight crew was alarmed in part because the men ignored instructions to stay seated with seat belts fastened during air turbulence, and instead retrieved "small black boxes fastened with what appeared to be black tape" from their luggage in the overhead bins.