Leaflets have been distributed in Penzance and London encouraging people to gatecrash festivals, shoplift from chain stores and "pay for absolutely nothing" in Penzance on 9 August, two days before the eclipse.

Fears of a so-called "anarchy jamboree" come just weeks after an anarchist riot in the City of London in which 40 people were injured. It is understood that the leaflets had been circulated at the riots.

Some local residents were already fearing disruption, following the arrival of the first large group of new age travellers in the area.

And holiday camp operators had become concerned that people were going to cancel holiday bookings.

There are fears of links with the City of London rioters

But Devon and Cornwall Assistant Chief Constable Alan Street reassured holidaymakers that they would be quite safe.

"We have a clear message to everyone who is planning to come to the south-west during the eclipse period - don't be put off by alarmist publicity," he said.

"We have been aware of these leaflets for some time.

"We are gathering intelligence on their source, and the situation is being closely monitored.

"We have been planning for the eclipse for many months, and we will deploy police officers wherever necessary."

Sit-in at McDonald's

The A4-size leaflets also said cars in the Penzance harbour car park would be smashed up and said: "The police will be powerless to prevent us - go ahead!

The "jamboree" is planned for two days before the eclipse

"This is your day, your freedom, your world. You owe nothing to landowners or club promoters."

It also proclaims the "right to roam, right to rave and right to love" and says there will be a "sit-in" at McDonald's in Penzance on 9 August.

"Reclaim the streets, reclaim the world, reclaim love", ended the leaflet - purporting to be distributed by the non-existent company Radon Communications Ltd.

Eclipse 'is world stage'

Mike Rosendale, countryside officer for the Penzance-based Penwith District Council, said the leaflet showed the danger of extremist groups using the eclipse as a platform.

He said:"The world's media will be here. It will be a world stage. It may be seen as an ideal platform for promoting their ideas.

"We are also aware of the potential problems with new age travellers and we have set up quite extensive measures to deter them."

But Mr Street said it was unlikely that violence would break out.

"Whilst it would be wrong to dismiss such leaflets out of hand, the public can have confidence in us and in our contingency plans," he said.