Hundreds of French fishermen clashed with police in Paris and severely disrupted cross-Channel traffic on Wednesday as they stepped up a 10-day-old protest against soaring fuel costs.
The fishermen, who have blockaded ports and oil depots for the past 10 days, hurled flares at police guarding the agriculture ministry where industry leaders were holding talks with the government. Officials said four police were injured.
On the Channel coast, hundreds of ferry passengers were left stranded as cordons of fishing boats blockaded Channel ports, including the main hub of Calais.
The British port of Dover was closed to ferry traffic as a result of the French blockade, causing a tailback of trucks on the main highway from London.
Operator Seafrance said it had three ferries waiting to leave Calais and two in Dover. Ferry traffic was also disrupted out of Dieppe, Boulogne-sur-mer and the Breton port of St Malo.
Passengers in France were being rerouted towards other ports such as Cherbourg or Le Havre, or to the Channel Tunnel, where
Eurotunnel trains were running as normal.
Eurotunnel said it had stepped up services to try to accommodate the extra passengers.
French trawler operators and crew are demanding the government increase a three-year 310-million-euro (480 million dollar) rescue plan for the industry.
President Nicolas Sarkozy promised on Tuesday to help the fishermen cope with the cost of their diesel, which has almost doubled to 70 euro cents per litre since November.
Some 300 fishermen gathered outside the agriculture ministry in Paris where Agriculture and Fisheries Minister Michel Barnier met with industry leaders.
The rally turned violent as protesters set fire to a European Union flag in protest at fishing quotas, and hurled around 100 flares and smoke grenades at police.
The talks were suspended for several hours after fishermen laid out their demands for a cap on diesel fuel prices, at 40 cents per litre.
"We will stay at the ministry until we get what we want," said Mourad Kahoul, vice-president of the national fisheries committee. "We'll bring mattresses if need be."
The fishermen, who have also ransacked fish stands at half a dozen supermarkets, have warned they will step up their protests unless their demands are met.
"We will not lift the blockades and we are ready to block oil terminals," said Kahoul.
Their protest movement spread this week from the Atlantic and Channel to the Mediterranean, and included fuel depots, commercial ports and pleasure marinas.
Motorists rushed to stock up at filling stations near La Rochelle on the Atlantic, and shortages were reported near Montpellier on the Mediterranean coast on Tuesday.
Dozens of fishermen blocked road access Wednesday to oil depots in Fos-sur-Mer and Berre, near France's number one port, Marseille, causing a tailback of fuel trucks waiting to take delivery.
A depot was also blocked in Bassens on the Atlantic coast.