Rogue bikers using machines like this one are abusing the moor land tracks

North Yorkshire Police are working with the National Park Authority and responsible bikers' clubs to clamp down on the rogue off-road riders.

Complaints include one where bikers allegedly pulled a "wheelie" through a full car park.

Local motorbike clubs are supporting the police action.

Doing 'wheelies'

In one instance a National Park voluntary worker was working on part of the Cleveland Way National Trail when eight off-road bikers refused to stop, forcing the man to leap out of the way.

Police say the incident was reported to them by the worker who was "very shaken, but not physically hurt".

In another incident the National Park office took a call from a member of the public who complained about a large group of bikers in a car park at Roseberry Topping.

The caller told the office some of the riders "did wheelies through the car park with children and families around before 'roaring off' up the hill".

Wildlife disturbed

A spokesman for the park's Recreation and Access department said: "It is not only illegal to ride on land that is not part of a road, but it is extremely dangerous to other people out in the countryside.

"National Parks are for everyone to enjoy and a small number of people are ruining it for everyone else.

"Livestock and wildlife are disturbed and the landscape is becoming scarred by this thoughtless activity."