Separatists in riot-hit New Caledonia refused Monday to abandon road blocks that have paralysed much of the Pacific archipelago and halted commercial air traffic, defying a major security operation by French forces.

France has sent 1,000 armed police, troops, and national security reinforcements to its overseas territory, a popular holiday destination rocked by seven nights of violence that have left six dead and hundreds injured.

New Caledonia, with a population of about 270,000, has been convulsed since May 13 by the unrest, sparked by French plans to impose new rules that would give tens of thousands of non-indigenous residents voting rights.

Some 600 heavily armed French police and paramilitaries have "neutralised" 76 road blocks on the 60-kilometre (40-mile) route between the capital Noumea and La Tontouta International Airport, officials said.

The airport remains closed to all commercial flights.

Hailing Sunday's operation as a "success", the French high commission in New Caledonia said forces would remove burned-out vehicles littering the key route for essential food and material supplies.

Pro-independence, largely Indigenous Kanak activists, said they would not release their chokehold.

Access will be closed

"We are maintaining our road blocks in place," said a statement by the so-called Ground Action Coordination Cell, or CCAT, some of whose leaders are under house arrest on suspicion of being behind the riots.

Roadblocks would be closed to all vehicles during night time curfews except for health emergencies and firefighters, the group said.

Indigenous Kanaks had suffered from discrimination for too long, it said, insisting that it sought a peaceful resolution but criticising the French "colonial state" plan to expand voting rights.

AFP journalists said some road blocks that had been taken down by the French security forces were being rebuilt by pro-independence forces, sometimes larger than before.

A fire overnight had reduced a construction firm's building to cinders.

A pickup truck drove through one Noumea suburb with about 10 masked and hooded men wielding machetes, AFP correspondents saw.

Anti-riot blast balls, often used to release tear gas or pepper spray, could be heard in one suburb of Noumea during the night, they said.