Reports from New Caledonia say a group of men broke into the staff quarters of the SLN nickel compamy in Kouaoua, setting a house on fire and burning a vehicle.
The media reports said about five individuals broke into several houses at night, including the home of the site manager.
The reports said the families living there had been evacuated.
There were no reports of any injuries.
The nightly attack came amid a restriction on movements because of the Covid-19 outbreak.
To contain lawlessness, a nightly curfew had been declared in Dumbea, near Noumea.
SLN's Kouaoua site, which is on the east coast of the main island, had been a frequent target for arson attacks, in particular in 2018 when operations were interrupted for weeks.
The site provided ore for the smelter in Noumea.