A charter plane carrying 148 Celtic football fans has been forced to make an emergency landing at Cardiff International Airport after reports of a major public disturbance on board.

The Boeing 737, en route from Santiago in northern Spain to Glasgow, was carrying supporters home after their team's Uefa Cup game against Celta Vigo and was due to arrive at 1535 GMT.

The incident is at a relatively early stage. We have sent officers to the scene South Wales Police spokesman

In a "full emergency" situation, South Wales Police boarded the plane - now on the runway at Cardiff - to take statements from crew members and passengers.

Several passengers were removed from the plane for further questioning. At least six arrests were made.

Police said six males from Glasgow were arrested - two 37-year-olds, and others aged 40, 42, 45 and 51.

They were arrested on suspicion of violent disorder and taken to Barry police station.

The remaining fans will be sent back to Glasgow on a bus.

The Royal Air Force at Kinloss in Moray was alerted shortly after 1500 GMT and scrambled two helicopters - on exercise in the Bristol Channel - as a precaution before the plane's crew elected to divert.

The plane landed at Cardiff at 1517 GMT. Nine fire engines and ambulances joined police at the scene.

'Unruly' passengers

Ian Macauley of airline Astreus told BBC News 24: "It became apparent during the flight that a number of passengers were becoming unruly.

"The captain adjudged the situation was such that he should divert to Cardiff.

"The aircraft landed safety at Cardiff and there have been a number of arrests - a number of people have been removed.

"We understand somebody may have been smoking on the aircraft, which is completely forbidden.

"When the passenger's ways were pointed out, a number of people got involved in something which became a fracas."

It is not known whether alcohol played a part in the incident, which one member of crew described as a "riot" at one point.

Helicopter scrambled

According to passenger Steve Prince, the pilot told passengers they would be detained on the runway at Glasgow.

"After that, there was a discussion between one of the passengers and the cabin crew - it was a little bit heated but not too bad," he said.

"One of the passengers leaned over and tapped one of the cabin crew on the shoulder.

"The next thing, we were descending at a rapid rate and heading to Cardiff.

"I'm a little surprised to hear there had been a riot on board. There were not any fierce postures taken."

He claimed "no alcohol whatsoever" had been sold or consumed on the plane.

A Celtic FC statement read: "We are extremely concerned about the reports we are receiving, both about the seriousness of events and the safety of our supporters.

"We are awaiting more information but currently understand that the flight was not an official Celtic charter and was not arranged through Celtic Football Club."