The increased police presence follows a violent incident at St Agnes Head near Perranporth, where about 70 vehicles and 120 travellers have converged for the eclipse.

Reports say that travellers clashed with police as they tore out a gate to allow another traveller's vehicle onto the site.

The camp, which has been growing steadily for several weeks ahead of the 11 August event, has alarmed local residents, tourist officers and farmers.

But the travellers insist that they intended their stay in the area to be peaceful and cause no nuisance.

The BBC's Jane O'Brien: "Moving the convoy could cause more problems"

The National Farmers' Union has set up a round-the-clock hotline to advise members on preventing travellers entering their land.

Celia Heal of the St Agnes Tourist Information Office said the convoy had affected tourism, with holidaymakers being advised not to go to the area of outstanding natural beauty.

Eviction order

St Agnes Head usually attracts holidaymakers who want a quiet, peaceful holiday, she said.

But the area has been surrounded by "more police than we've seen in our lives", said Ms Heal.

The travellers say they want to watch the eclipse and then move on

Ms Heal said the local authority,Carrick District Council, should have acted sooner, as the first vehicles on the convoy arrived "several months ago".

The council has won a county court order against the travellers but said it may not be practicable to move the convoy until after the eclipse.

The convoy could cause worse problems elsewhere, it said, and moving them would put a strain on the emergency services.

Peaceful intentions

Chief Superintendent Bob Sturland of Devon and Cornwall police said officers were prepared to move in extra resources.

All roads leading to the headland had a police presence and officers were on foot patrol around the area to reassure local residents, he said.