New Caledonia's Kanak union has set up blockades at mines and some government administrations in a territory-wide campaign in support of a nickel plant in the northern province.
The USTKE union has begun a general strike that has paralysed construction work at the Goro nickel plant in the south of the main island.
In a protest directed at the French state and the French state-owned conglomerate Eramet, the mines of its subsidiary SLN have also been blockaded but the smelter in Noumea is reported to be working.
The USTKE members have besieged the administration in La Foa, Kone and in Lifou in the Loyalty islands where police also report sit-ins in Ouvea and Mare.
The action comes as Eramet has sought a court ruling on the Koniambo ore deposit which is at the centre of negotiations for a smelter in the north.
The Canadian company, Falconbridge, says it will fully fund the 2.2 billion US dollar project after disagreements with France over the way forward for the project.
The issue has prompted a mass rally in Noumea last weekend as a 1998 agreement stipulates that an irrevocable project for a smelter has to be started before the end of December for the Kanak northern province to get the Koniambo ore.
A Falconbridge team is on its way to Noumea to finalise the deal.