Riot police have tackled yobs at Aberdeen-Rangers games

Banning orders were introduced in England and Wales in 2000 to prevent convicted troublemakers from travelling to matches at home or abroad.

Scottish ministers are now looking at a similar crackdown, in the face of a comeback by football "casuals".

Strathclyde Superintendent Kenny Scott said keeping thugs out of grounds would have a "tremendous effect".

Rivalry between Rangers and Aberdeen has led to some of the worst violence in Scottish football.

Supt Scott told BBC Scotland's Frontline programme: "The introduction of banning orders would be the single most effective tool that we don't have at present in our armoury in dealing with hooligans and persons convicted at football matches."

You drink loads of beer, abuse policemen, fight with other lads. It's just the best buzz Dougie Brimson Author

He said: "What a tremendous effect that would have in stopping people who are intent on disrupting the enjoyment of the normal everyday punter."

As many as 200 police can be on duty for category A matches - those which need the highest level of security.

An undercover officer said: "On match days I am sometimes employed as a spotter, gathering real-time intelligence from licensed premises, pubs or train stations.

"We go out in plain clothes looking for ringleaders from the hooligan groups concerned.

"Once we find them, from their demeanour we can usually tell whether something's planned or not. They'll be agitated on their mobile phones."

'Mob' pub

One casual admitted: "You live and breathe it. You know, you could be sitting in a pub with your wife and thinking this would be a good pub to bring a mob to."

Football hooliganism author Dougie Brimson said: "The big thing, and it's the point everybody misses when they are talking about hooliganism, is that it is the best fun to go to the other end of the country with a group of your mates.

"You drink loads of beer, abuse policemen, fight with other lads, fight with local police and come home. It's just the best buzz.

"There are those who will go purely for violence but they are the sort of guys who are just violent.

"For the most part it's about clothes, bravado, football, messing about, getting drunk and having the odd row."