The New Caledonian union group protesting against the high cost of living has blocked access to the port of Noumea.
The port is the latest target of what it calls a general strike launched last Wednesday.
The protest began with a huge march to seat of the government which on Friday announced it planned to drop tariffs on food stuffs from non-European Union countries.
On Tuesday, the strike prompted about 2,500 people in the north of the main island to take to the streets, calling for lower prices.
The protest action was called after the unions accused the government of failing to implement reforms agreed on following unprecedented territory-wide demonstrations two years ago.