It was an unprecedented move in an industrial dispute.
French commandos raided a Corsican ferry that had been commandeered by striking sailors and forced it to turn back to the French mainland.
The operation took around 10 minutes and was praised for its non-violent outcome by the interior minister.
The workers who seized the vessel could face up to 20 years in prison as, under French law, their action is considered to be as serious as hijacking a plane.
They took over the SNCM ferry in Marseille and sailed towards the port of Bastia in Corsica.
The French military soon spotted it. To avoid capture, the ferry did not attempt to dock but weighed anchor overnight at the entrance to the harbour.
The action was a further protest against the government’s privatisationplans. SNCM is to be sold off to an investment company. The government says it will retain a symbolic stake of 10 to 15 percent, but that is unlikely to mollify workers.
In the Corsican city of Bastia, violence errupted as the strike went into its second night over fears of job losses. The ports of Bastia and Marseille are still blockaded.
The European Commission says it is following the developments closely.