Vessels from Britain's Royal Navy and French police boats patrolled Thursday near the English Channel island of Jersey, where French fishermen angry about losing access to waters off their coast gathered for a maritime protest.
The irate mariners set off flares and entered the island's main harbour, in the first major dispute between France and Britain over fishing rights in the wake of Brexit.
The European Union appealed for calm, but also accused the UK of not respecting the terms of the post-Brexit trade deal agreed to by the two sides.
The naval policing boats Athos and Themis were sent to keep watch on waters between France and Jersey, French maritime authorities for the English Channel and North Sea said.
The deployment came after Britain on Wednesday directed two naval vessels, HMS Severn and HMS Tamar, to also patrol the waters around the island, a self-governing British Crown Dependency near the coast of northern France.
French fishermen steamed into Jersey waters to demonstrate against new post-Brexit rules requiring them to submit their past fishing activities in order to receive a license to continue operating in the island's waters. French fishing communities say some boats that have operated around Jersey for years have suddenly had their access restricted.
Dimitri Rogoff, who heads a grouping of fishermen, said about 50 boats from French ports along the western Normandy coast joined the protest Thursday morning, gathering their fleet off the Jersey port of St. Helier.
He said the protest over licenses for French fishermen was not an attempt to blockade the port.
“This isn't an act of war,” Rogoff said in a phone interview. “It's an act of protest.” Jersey fisherman John Dearing said the scene off St. Helier was “like an invasion.” “It was quite a sight,” he told British news agency PA. “It was impressive, I looked from the shore this morning and it was just like a sea of red lights and flares already going off at sea.”
French authorities said the patrol vessels were there to assist in any maritime emergencies.
“We would thus be capable of intervening rapidly should the situation worsen, which is not the case at the moment,” they said in an emailed statement to The Associated Press.
The British government said its two navy vessels “would remain in place to monitor the situation as a precautionary measure.”
Opponents accused Prime Minister Boris Johnson of escalating the crisis, and of using the fishing spat as an Election Day stunt. The story dominated newspaper front page on Thursday, as voters go to the polls in local and regional elections in England, Scotland and Wales.
There have been numerous bouts of friction in the past between French and British fishermen.
The latest dispute, the first since Britain's departure from the European Union last year, came after the island implemented new requirements that make fishermen account for their past work in Jersey waters to be eligible for a license to continue operating there.