TWO tribes face each other across the killing ground. Scores of them ready to do battle, bloodlust running high. Some are armed, others ready for hand to hand combat. Intoxicated with liquor, dressed in their unique colours and chanting an offensive litany, they clash, fists and feet flying, scratching, gouging their opponents, smashing, crashing, bashing, causing mayhem.

Some of the violence is planned, much is spontaneous, a physical outburst sparked by ethereal notions of aggression, pride and booze.

It's a primitive scene and a familiar one throughout the millennia. But this time the backdrop is a modern one. These are sports fans; but not just any sport, they have the common love of football.

Man has always fought man; it's human nature. The reasons are irrelevant; territory, culture, religion, sex. Man looks for an excuse for a fight and being a fan of a rival football team is more than enough for some.

Football attracts a hooligan element bringing shame on the country, with violent scenes like those at this year's Euro 2000 and individual acts of sheer victimisation such as the incident at the Manchester derby game on Saturday when David Beckham was hit on the head by a coin. When Leeds played Turkish side Galatasaray in April, the sport plumbed new depths when two fans were murdered in Istanbul.

The recent World Cup qualifiers between England, Germany and Finland were better, passing off without serious incident. But hooliganism returned when Leeds again played in Istanbul, when Besiktas fans hurled missiles at an injured player.

Assistant Chief Constable of Durham Constabulary Ron Hogg knows the problem only too well. He is charged with policing football matches, both in this country and abroad.

"It's the laddish culture. Young English males going out binge drinking. These are the kind of people causing disorder in our towns and cities at the weekends and in Ibiza on holiday. It then spills over into following England. It's not so much a football problem as a much more deep-seated social issue."

A big football fan himself, a Newcastle United supporter, Scottish-born Mr Hogg believes it is only a small minority who cause the trouble compared with the millions of supporters worldwide.

"Football does stir the passion, it is an exciting game. But the troublemakers put a label on it and organise the trouble. It's something to do with identity and tribalism. For the organisers it is about power, having the ability to influence and cause mayhem. It seems to be a human trait which is why you can never eradicate it."

Big games invariably attract big problems and are policed accordingly. Locally, police officers know from bitter experience which fans hate whom and local derbies always attract a heavy police presence.

International matches are gauged too. England versus Germany or France has great potential for trouble, Turkey even more so because of the violence last time. But matches against Portugal or Albania are likely to pass uneventfully.

"We judge them on the basis of intelligence and from what we know from the past," Mr Hogg says.

"When England play abroad we will take with us a team of spotters, football intelligence officers drawn from various different forces with experience of big clubs, such as Newcastle, Arsenal, Chelsea or Leeds. They operate as spotters for their own clubs and will work with the local police forces."

Spotters pinpoint where the fans are likely to drink, where the troublespots will be and the mood of crowds. They also watch out for known hooligans as they arrive at the airport, picking them off before they can mobilise the trouble, and making use of the intelligence gathered on them all year round, which is held on a national database.

The team also includes a match commander, currently Northumbria superintendent Graham Stafford - a veteran of countless Newcastle United matches - and a sergeant from the National Criminal Intelligence Service, who co-ordinates the English spotters, deploys them with local forces and feeds them what intelligence there is.

"They link in with the local police and advise on the likely behaviour of fans," Mr Hogg says. "They've become exceptionally good at their job." He then takes a strategic view, working closely with foreign senior officers, the British consular officials, the Home Office and liaising with the media. If English fans need deporting, he will set up the necessary procedures.

He is also in touch with every force in the country, keeping them abreast of the hooligans issue, Government ministers and Football Association officials. At the end of the season he will organise and host an annual conference in Durham, at which crowd safety will be discussed by police, FA and league officials.

It's far from an easy job. Hardened hooligans are a wily lot and go to extraordinary lengths to avoid detection, at considerable cost to themselves. Some sell their worldly goods to get to matches, others are already career criminals using ill-gotten gains to get to the games. For instance, they will fly hundreds of miles out of their way and use a variety of foreign airlines to evade spotters scrutinising flights from Britain.

Trouble is planned and prearranged over the Internet and by using mobile phones. Once it breaks out, many of the ringleaders simply sit back and watch to avoid arrest.

There are also language problems to overcome between the various police forces, cultural divides and different policing methods to sort out.

For instance, in this country anyone seen causing trouble is arrested and dealt with by the courts. Abroad, if there is trouble in a particular area and the police charge the crowd, everyone is arrested and then deported without charge. This means many innocents are caught up with the guilty who themselves avoid conviction and therefore a police record for football hooliganism.

"So the minute trouble flares the organisers walk away and the police focus on the disorder," Mr Hogg says. "We try to tackle the disorder on a long term basis and take the trouble makers out through banning orders."

The orders are just one of a host of new weapons in the official armoury designed to stamp out football hooliganism.

If hooligans are convicted by a court, they can be banned from all matches and there is the power to seize passports. Police can also approach the courts to ban fans who have not been convicted of any related offences when there is evidence they are troublemakers.

At any time in the five days before a major match, known hooligans can be detained by police for four to six hours to investigate intelligence alleging they are troublemakers. Police can also secure a notice for the fans to appear before magistrates within 24 hours for the consideration of a banning order. Again this can be timed so they miss the match.

Troublemakers come in all shapes, sizes, sexes and classes. Fighting alongside the unemployed and the labourers are often professionals, including solicitors, engineers and computer experts, predominantly men but a few women as well. The main culprits are aged 20 to 45.

Unacceptable behaviour includes fighting and criminal damage and also making threats and singing racist songs.

Policing the hooligans is a difficult job and the reputation of the country and Mr Hogg's force is on the line every time there is a big match.

"It's fascinating and a dimension of policing I didn't imagine I would end up doing," he says. "If things do go wrong it's people like the Home Secretary who ring me up asking me why.

"Genuine football fans don't want these hooligans and, if anything, being a fan myself doubles my resolve to do all I can to take these people out."