A quick response team will be on standby at high risk periods

Potential sites will be monitored and a quick response team will be on standby for any signs of disturbance.

Last August, hundreds of revellers took part in a three-day rave on land at Marloes Court Farm in Marloes, Pembrokeshire.

They set up their own sound system and farmer Owen Morgan said he felt 'powerless' to move them on.

We have had complaints about noise, litter and damage to property such as fences and gates PC Mark Holman

Officers carried out spot checks on people arriving but although the event was illegal because the entertainment was unlicensed, Mr Morgan said he was told the trespass aspect was a civil matter.

A similar situation happened at Whitesands near St David's provoking complaints from holidaymakers and locals.

Dyfed-Powys Police has teamed up with Pembrokeshire Council, the National Park Authority, National Trust and other groups to try and avoid a repeat.

Pc Mark Holman said during high-risk periods such as bank holidays a team would be on standby to respond to any incidents.

'Spoil the enjoyment'

He said organisers could be prosecuted under the 2002 Police Reform Act which gave officers power to seize private vehicles.

But he said the most effective way to prevent such raves was to act before they started and landowners were being encouraged to report any warning signs.

"Some of these events took place on land where the owner had not given consent," he said.

"When these events have happened in the past there has been disruption for land owners and people living nearby.

"We have had complaints about noise, litter and damage to property such as fences and gates."

He said there were several licensed music festivals planned in the county during the summer and these were going ahead with the cooperation of the police.

"We happy to work with the organisers of any organised events," he added.