Police in New Caledonia have opened an investigation into yet another fire at the nickel mine in Kouaoua - the 14th this year.
Reports said the arson attack on the site's conveyor belt came in the night after more than 60 police removed a barricade blocking the site.
The police acted after a court in Noumea authorised the expulsion of a group of local men who had set up the barricade at the beginning of the month.
The mining site, which is owned by the SLN nickel company, had already been closed for more than two months from August but an agreement had been reached in late October for operations to resume.
The belt system feeds nickel ore to the coast for shipping to the SLN smelter in Noumea, with the Kouaoua mine providing about 40 percent of SLN's ore.
The earlier blockade is estimated to have incurred SLN losses of almost $US20 million.