Previously, 100 people had to be gathered in an open space before officers could take action.

The new order gives them powers to break up a crowd of 20 or more people in open or indoor areas.

And anyone who is moved on faces arrest if they try to start up another gathering within 24 hours.

The force is believed to be one of the first in the country to adopt the new legislation under the Anti-Social Behaviour Act 2003.

'Early Action'

Operational planning head, Superintendent Adrian Coombs, said police could now deal with incidents more effectively rather than relying on public order legislation.

"In the past we've had a situation where officers realised they could do little until a rave had been going on for some time, meaning serious disruption to both local people and officers.

"Now officers will have the power to take early action to prevent a rave getting off the ground in the first place," he said.