Police have stepped up operations to prevent illegal raves taking place in Suffolk over the Bank Holiday weekend.
The public and landowners are being urged to report any suspicious activity around land or disused buildings.
They should also report any sightings of lorries or vehicles gathering near woods or rural car parks, or sightings of fliers advertising raves.
The action follows an illegal rave in Ramsholt last August in which 10 people were arrested and three later fined.
Suffolk Police also arrested 14 people following an illegal rave in Elvedon in April this year.
Supt Mike Shields said: "Plans are under way to ensure we prevent and deter any illegal raves taking place across the county.
"Landowners are asked to be vigilant and make sure their land is as secure as possible.
"Organisers of raves will sometimes cut locks on gates or outbuildings the day before the rave is planned to start, so if you find your security has been tampered with call the police immediately."