Opponents on both sides of the speed camera debate today clashed over a new report which indicates they have saving more than 100 lives a year.

The number of people killed or seriously injured at camera sites nationwide fell by an average of 40 per cent over the three years to mid-2003, an independent study across a number of police force areas showed.

But figures for individual camera sites revealed that some in cases the number of accidents had actually risen since their installation.

In Cleveland - the only safety camera partnership included in the Government backed report - it was confirmed that the overall number of accidents involving personal injury had dropped by 366 or 50 per cent in the last three years.

At some sites though, the number of people killed or seriously injured had more than doubled, albeit from a low level.

Examples of such sites included in the Department for Transport figures, were the A171 at Charltons, near Guisborough, Cargo Fleet Lane in Middlesbrough and the A172 between St Lukes and Marton Crossroads, also in Middlesbrough.

Last night Mick Bennett, manager of the Cleveland Safety Camera Partnership, said that statistically such rises "meant nothing".

"You have to look at the success of the partnership overall and say what has been achieved altogether."

Teesside-based Brian Gregory, of the Association of British Drivers, said: "When the figures are in their favour that it is because of the cameras, but when they show any increase that is put down to a natural statistic variation."

Mr Gregory added: "The speed issue is largely a red herring as most accidents are not caused by this - they are caused by people not paying attention to the road.

"People need to focus on what is going on around them and focusing on the speedometer does exactly the opposite."

Earlier this year it was revealed that almost £2m has been raised in the last 12 months from cameras sites in Cleveland.

The publication of the new independent report is intended to deflect criticism that cameras are simply cash raising devices which play no part in improving road safety.

Transport Secretary Alistair Darling said the figures proved ''that cameras save lives''.