CALAIS, France (AFP) – A strike by French ferry workers caused severe disruption on both sides of the Channel on Friday and union bosses warned the action could stretch into the busy Easter holiday weekend.

SeaFrance workers in Calais walked out over new working practices and what they say are insufficient staffing levels, leaving two of the company's ferries stuck in the northern French port.
About 1,800 passengers on board one ferry, the Berlioz, were forced to leave the ship in Calais without making their crossing to the English port of Dover.
Another ferry was eventually allowed to dock in Calais after waiting out at sea for several hours, and 1,200 passengers on board were able to disembark.
Striking workers then prevented the ship from making the return crossing to Dover.
Unions said the strike would continue on Saturday.
"The strike is set to last at least 48 hours," said Didier Cappelle, of the CFDT union.
Roads around Dover were gridlocked as a result of the strikes, forcing police to line up lorries waiting to cross to France. The vehicles stretched along the M20 motorway.
SeaFrance's managing director, Robin Wilkins, apologised for the disruption and urged passengers to stay away from the port.
"This is a very, very short notice strike which has blown up this morning," he said.
"I think it's a disastrous and very regrettable decision, calculated to have the maximum effect on customers."
SeaFrance, which has suffered a fall in its freight traffic, passed plans in December to cut 482 jobs from its 1,580-strong workforce in the face of strong opposition from unions.
Employees have complained of a lack of crew for night crossings as a result of new working practices.
The company normally operates between 16 and 19 crossings a day between Calais and Dover.