Image copyrightAPUnconfirmed reports of gunshots, later described by police as just “loud noises”, have sparked evacuations at Los Angeles airport.
People fled the airport on Sunday night amid the shooting reports, with scenes of abandoned luggage on pavements.
Traffic to the terminal was closed and no flights were allowed to land, but operations have now resumed.
LA police tweeted that no shots had been fired and there were no injuries. They are investigating the noises.
The police and fire departments had deployed many units to the airport after reports of a “security situation” and a possible “active shooter”.
Los Angeles airport tweeted that an individual in a “Zorro” costume had been detained.
One passenger, Scott McDonald, told Associated Press he had been trying to disembark from a plane and had been told to get back on.
He said he had seen many people gathered on the tarmac.
Actress Anne Dudek told the LA Times she had been on an escalator when a man ran past saying people were being shot.
“People started dropping bags and running out of the terminal,” she said. “Panic spread.”
She said she had also left the terminal and run through a parking area to her car and left the airport.
The Federal Aviation Administration temporarily held some Los Angeles-bound flights.
Passengers were later allowed to return to the terminal to gather luggage left behind.
Los Angeles International Airport (LAX) is the world’s seventh busiest by traffic.