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

France has sent 1000 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 since May 13 been rocked by 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 had "neutralised" 76 roadblocks on the 60-kilometre route between the capital Noumea and La Tontouta International Airport, officials said.

Qantas told the ABC that Noumea Airport would remain shut "due to continuing civil unrest".

"We're in close contact with DFAT [The Department of Foreign Affairs and Trade] and Noumea Airport authorities and preparing to respond quickly to help get people to their destinations when it reopens.

"We will continue to contact impacted customers directly with a range of options, including refunds," a spokesperson said in a statement.

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.

However, the pro-independence, largely Indigenous Kanak activists said they would not release their chokehold.

French Prime Minister Gabriel Attal said on Monday (local time) that "we are still a way off a return to normal".

"We are maintaining our roadblocks in place," a statement by the so-called Ground Action Coordination Cell said, 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 roadblocks that had been taken down by the French security forces were being rebuilt by pro-independence forces, in some cases larger than before.

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

A pick-up truck drove through one Noumea suburb with about 10 masked and hooded men wielding machetes, according to eyewitness accounts of AFP correspondents.

"It feels like being in the The Walking Dead," local post office director Thomas de Deckker said, referring to the post-apocalyptic zombie television series.

"We have no visibility of when we will have security again," he said.

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.

"The islands are on fire, for sure, but we have to remember that they tried to be heard for a long time and it led to nothing," resident Laloua Savea said.

"It had to degenerate for the state to see us, for the politicians to see us," she said.

"They must be heard, even if they are going about it the wrong way."

Authorities said about 230 people had been detained and an estimated 3200 people were either stuck in New Caledonia or unable to return to the archipelago, which lies more than 1000 kilometres east of Australia.

French President Emmanuel Macron has called a meeting of his defence and security council for Monday.

On Friday, Prime Minister Gabriel Attal met leaders of the parliamentary parties to discuss whether to extend the state of emergency beyond its initial 12 days.

That would require the approval of both the lower house National Assembly and the upper house Senate.

New Caledonia has been a French territory since the mid-1800s.

Almost two centuries on, its politics remain dominated by debate about whether the islands should be part of France, autonomous or independent — with opinions split roughly along ethnic lines.

Indigenous Kanaks make up about 40 per cent of the population but tend to be poorer and have fewer years of schooling than European Caledonians.

Kanak groups say the latest voting regulations would dilute the Indigenous vote.

- ABC/AFP