IMAGINE the scenario – Peterborough United Football Club have just lost at home to Norwich, and Posh fans are not happy. After making a barricade across a street outside the stadium, using cars and whatever else they can get their hands on, the 100-stron

IMAGINE the scenario - Peterborough United Football Club have just lost at home to Norwich, and Posh fans are not happy.

After making a barricade across a street outside the stadium, using cars and whatever else they can get their hands on, the 100-strong crowd becomes increasingly aggressive.

More than 100 officers from Cambridgeshire and Norfolk police are mobilised to deal with the disturbance. The situation escalates into a full blown riot with fans hurling bricks, tyres and petrol bombs at officers.

Luckily, this is only a police training exercise but from the roof of a Cambridgeshire RAF building it looked and sounded real.

"This is very dangerous, one false move and an officer could get badly hurt," said Pc Keith Curtis, a safety officer from Cambridgeshire Constabulary.

"We tell the officers to treat this as if it is real and we aim to create a sense of emergency and fear so the officers can put their training to the test."

Set up on the ground are two pubs, a football stadium and a road network complete with traffic lights, alleyways and junctions.

At the front line, college students play the rioting fans who confront the police at the barricades hurling bricks and tyres. One of the students said: "This is great fun - to be allowed to throw things at the police is awesome. We were told to be as tough as we could and were given trolleys of bricks to throw at officers. It was exciting but quite scary when we were pushed back by police."

Also on the ground are angry men, police officers dressed as civilians who antagonise officers by shouting abuse and hitting them with baseball bats. Smoke grenades were also thrown at officers, forcing them to confront the rioters with restricted vision.

Pc Curtis said: "This is just another distraction the officers have to be prepared for. It is about making them aware that anything can happen."

The officers are kitted with helmets, shields and fire protective clothing and look safe enough, but at one point an officer's leg is set on fire by a petrol bomb and a fire extinguisher has to be used to put it out. "The officer's kit is fire retardant so he is quite safe," said supervising Chief Inspector Gary Martin, as we watch the officer dance around like a River Dance performer trying to put out the blaze.

"We update the kit when we become aware of weaknesses." In 2001 padding was added to the top of the boots as a result of rioters pushing tiles off roofs and injuring officers' feet.

Also covered on the training day were simulated injuries including an officer with a broken ankle. Chief Insp Martin added: "We can't expect ambulance crews to enter a riot so we have to be prepared for anything including medical emergencies and that means training officers as paramedics."

Inspector Carl Richards from Norfolk police, who took part in the exercise, said it is the closest they got to the real thing. He said: "We treat this event as if it is real because that means we get the most out of our training."

Chief Insp Richards attended the 1985 Broadwater Farm Housing Estate riots in Tottenham where one policeman died. He said: "The rioters threw tins of dog food at us because that was the only thing they didn't want to steal. I hadn't been on a riot training course like this when I was sent to deal with the Tottenham riot and had only been in the job six months. I was given a shield and told to get on with it. The training you saw today would have really helped."

Chief Inspector Gary Martin, who supervised the training exercise, has also had first hand experience of riots. He said: "I attended the 1982 Belfast Poll Tax riots. It was different to what we taught today as it was out of control and not expected so we couldn't plan for it. What the officers did today is the worst they are likely to expect. Although it was staged the officers were under threat, in danger and under pressure and many would have left with cuts and bruises.