American Airlines said a flight to London returned to Miami because a passenger refused to comply with the federal mask requirement, the latest flight disruption over a report of an unruly passenger.

American Airlines Flight 38, a Boeing 777 with 129 passengers and 14 crew members abroad, turned back for Miami late Wednesday about an hour into the trip, according to flight-tracking site FlightAware.

The return was “due to a disruptive customer refusing to comply with the federal mask requirement,” American said in a statement. “The flight landed safely at MIA where local law enforcement met the aircraft. We thank our crew for their professionalism and apologize to our customers for the inconvenience.”

The traveler has been banned from flying the airline pending an investigation, the carrier said. The Miami-Dade Police Department didn’t immediately respond to a request for comment.

Reports of unruly behavior on planes surged to a record 5,981 last year, more than 71% tied to disputes over a federal mask mandate that went into effect early last year, though airlines had required them since the coronavirus pandemic began.

Some incidents included physical assault against crews. In October, an American Airlines flight attendant was hospitalized after a passenger allegedly struck her in the face, forcing the cross-country flight to divert.