A green guerrilla movement which claimed to have attacked 32 4x4 vehicles in Oxford has urged more activists to follow its lead.

The anonymous group claimed it let down tyres on cars in the city during a night of action last week to protest against global warming.

Police are checking links with European anarchists responsible for more than 1,000 identical incidents in Sweden last year and attacks in Edinburgh in March.

At least eight 4x4 owners in Marston and Headington reported to police they were victims of the vandalism.

The activists claim, via websites such as direct action site Earth First, that they targeted 32 vehicles.

Philip Norris, 49, of Weldon Road, Marston, owns a Toyota RAV4 and was one of many motorists whose tyres were let down last Thursday.

He said: "People want to make a protest which is fair enough, but it defeats the point when I have to run the engine for half an hour, and use a pump plugged into the cigarette lighter, to inflate my tyres. It isn't going to stop me using my car. I do not think this is kids just messing around, this is more serious."

Other incidents were reported to police at Ferry Road, Nicholson Road and Raymund Road in Marston and Grays Road, Jack Straw's Lane, Southfield Road and Staunton Road in Headington.

We found at least three more victims in Ferry Road. In each case, tyres were deflated and letters left on windscreens.

This anonymous posting can be found across the Internet. It includes: "Up to 32 SUV (Sports Utility Vehicles) owners awoke to discover that their destructive vehicles had been disabled.

"Using the 'mung bean trick', whereby a bean is inserted into the valve of a tyre before the cap is screwed back on, tyres were let down in Marston, Headington, and the highly affluent area of Summertown."

Former city councillor Sid Phelps, chairman of Oxford Green Party, said: "Let's not get too het up over this - it is quite inconvenient for people to have their tyres let down, but global warming caused by SUVs is pretty inconvenient for the rest of us."

Chief Insp Jack Malhi said: "Although we live in a democracy and respect the views and opinions of others, I would like to remind people that by taking the law into one's own hands and damaging other people's property is an unacceptable crime."