DENVER (AP) — Federal prosecutors say a 20-year-old California man has been charged with assault and interfering with a flight crew in an alleged assault on a flight attendant on a cross-country American Airlines flight.

Details of the allegations against Brian Hsu of Irvine weren't immediately available on Monday. The case was listed as sealed. It's not known if he has an attorney.

He was expected to appear in federal court in California’s Central District later Monday. The flight from New York to Santa Ana, California was diverted to Denver Wednesday because of the incident.

It was investigated by the FBI and didn't immediately result in an arrest.