Mounting concern over the spread of coronavirus was apparently behind a US flight being diverted at the weekend after passengers became upset over someone sneezing and coughing.

United Airlines told AFP in a statement that the flight -- headed from Eagle, Colorado, to Newark, New Jersey  -- was diverted on Sunday afternoon to Denver's international airport.

The plane was allowed to continue on to New Jersey after a small group of people who raised a ruckus over fears a passenger who was sneezing and coughing may be sick with the virus were taken off the flight, local media quoted officials as saying.

The airline said the incident "was in no way a medical situation."

It told local media that the passenger who was sneezing had allergies and was evaluated and allowed to stay on the flight.

"After landing safely, the aircraft was met by law enforcement" the airline said.