The pilot issued a Mayday distress call, an RAF Sea King helicopter was alerted and armed police, firefighters and ambulance teams were sent to Cardiff Airport, where the plane landed at about 3.30pm yesterday.

Angry Celtic football fans, returning home to Glasgow today, hit out at claims that there had a been a “riot” on board the passenger plane.

They said yesterday’s events had been blown out of proportion.

However, the Gatwick-based charter airline Astraeus, which operated the flight, said it now had a clear picture of the events that caused the pilot to divert to Cardiff.

Its spokesman, Iain Macauley, said there had been two disturbances on the aircraft.

The first, at the front, involved a passenger smoking, he said.

Mr Macauley added: “A senior cabin crew member pointed out that it was against air travel regulations to smoke on the aircraft.

“This passenger objected to being asked to extinguish his cigarette.”

He said the second incident occurred at the rear of the aircraft cabin, after the captain made a public address announcement stating that the behaviour encountered at the front of the aircraft would not be tolerated.

Mr Macauley said: “A number of passengers at the rear of the aircraft objected strongly and loudly, one female passenger becoming particularly agitated, and at least 10 other passengers became involved.

“In the ensuing fracas the cabin crew member was struck on the arm.”

He said she had been examined by paramedics on arrival at Cardiff, but no hospital treatment was required.

“It has become apparent from our debriefing of cabin crew that passengers in the forward and centre sections of the cabin may not have been aware of the second disturbance,” said Mr Macauley.

At that stage, a cabin crew member contacted the pilot, making it clear that the cabin crew felt matters were threatening the safety of the aircraft and the pilot made the decision to divert to Cardiff.