Dockers in Brégaillon port in Toulon-La Seyne-sur-Mer on Wednesday prevented the docking of two ships that had not been able to dock at Marseille.
They positioned two trailers on the quay, preventing the ferries’ gates from opening.
“We do not wish to be considered strike breakers by our colleagues in Marseille,” a union leader at the port told French press agency AFP.
The two ships went to another port in Toulon, where the dockers allowed only the passengers to disembark.
Dockers for the Société Nationale Corse Méditerranée, the company in charge of transport between Corsica and the mainland, have been on strike since 31 January, and have blocked the two entrances to the harbour in Marseille since Tuesday afternoon.
Five SNCM boats have been stranded in Marseille and in Bastia in Corsica for the last five weeks.
Plans to decrease the number of journeys between Nice and Corsica are the source of the conflict.