French fishermen have clashed with a number of British boats after a "scallop war" erupted in the English Channel.

Rocks, smoke bombs and other projectiles are reported to have been hurled at English and Scottish vessels during the confrontation in the early hours of yesterday morning.

Reportedly heavily outnumbered by the French, the British boats were allegedly attacked by the rival flotilla that had gathered overnight in protest over fishing rights.

Footage of the incident broadcast by France 3 Normandie showed the boats colliding as an object was thrown toward them.

Some of the British vessels are said to have later returned to UK harbours with signs of "criminal" damage.

The long-running dispute is over a scallop-rich area of the channel that French fishermen are prevented from harvesting due to domestic environmental laws.

French boats only have the right to fish for scallops from 1 October until 15 May to allow local stocks to regenerate, but the British do not face the same restrictions.

Dimitri Rogoff, head of a Normandy fishermen's association, said the violent scenes "demonstrate the exasperation of Normandy fishermen in a situation which persists and does not change."

"I urge everyone to avoid these situations that endanger men's lives," he said.

One of the British boats involved in the clash is said to be the Honeybourne 3, a Scottish scallop dredger.

The Scottish White Fish Producers Association condemned the "vigilante" French fishermen.

"Attacking our vessels is appalling," the group said.

Britain's National Federation of Fishermen's Organisations has appealed for calm, saying the dispute should be resolved through negotiations.

"We have raised the matter with the British Government and asked for protection for our vessels, which are fishing legitimately," said chief executive Barrie Deas.

"The deeper issues behind the clashes should be settled by talking around the table, not on the high seas where people could be hurt."