Burnt-out cars are seen in the parking lot of the old hospital on the outskirts of Noumea, French territory of New Caledonia, May 16, 2024. [AFP]

Hundreds of military and armed police reinforcements deployed Friday to the riot-scarred streets of France's Pacific territory of New Caledonia, seeking to quell clashes that have left five people dead and hundreds injured.

Anger over France's plan to impose new voting rules spiralled into the deadliest violence in four decades in the archipelago of 270,000 people, which lies between Australia and Fiji - 17,000 kilometres (10,600 miles) from Paris.

In Paris, Prime Minister Gabriel Attal said about 1,000 extra security forces were being sent to New Caledonia - adding to the 1,700 already present - while authorities would push for "the harshest penalties for rioters and looters".

Extra forces began landing Thursday at the French army-controlled La Tontouta International Airport and could be seen moving through the capital Noumea in red berets, toting rifles, gas masks and riot shields.

Using state of emergency powers, security forces had imposed "a calmer and more peaceful situation" around Noumea for the first time since the unrest started on Monday, according to the high commission representing the French state.

But there were "fires at a school and two companies", it said in a statement Friday.

Smouldering buildings

On Friday morning, AFP journalists saw flames and smoke pouring from a shopping centre, smouldering buildings, dozens of burned-out cars and residents dragging the remnants of vehicles off the roads.

Hundreds of people lined up outside shops for desperately needed food and supplies.

The security reinforcements will impose order "where control is no longer assured", High Commissioner of the Republic in New Caledonia Louis Le Franc told journalists in Noumea.

Security forces have placed 10 independence activists accused of organising violence under house arrest, according to authorities.

Two gendarmes have been killed: one shot in the head and a second shot in friendly fire, officials said.

Three other people - all Indigenous Kanaks - have also been killed: a 17-year-old and two men aged 20 and 36.

Burning tyres 

One person has been arrested on suspicion of killing two Kanaks, French authorities said. Another homicide suspect turned himself in on Friday, they said.

About 200 among an estimated 5,000 "rioters" have been detained, officials said.

Groups of Kanaks have set up roadblocks around the main island, waving the territory's flag, burning tyres and blocking or slowing traffic.

Other mostly non-Indigenous residents, some armed, piled up garden chairs, crates and other belongings in neighbourhood barricades.

The violence is the worst seen in New Caledonia since violence involving independence radicals rocked the French overseas territory in the 1980s.

TikTok has been banned in New Caledonia under the state of emergency because it was being used by the protesters, authorities said.

The social media giant called the decision "regrettable" in a statement and said that "no request or question, no demand to withdraw content, had been made by local authorities or the French government".

Between 80 and 90 percent of the grocery distribution network in Noumea - from shops to warehouses and wholesalers -- has been "wiped out", Chamber of Commerce and Industry president David Guyenne said.

The chamber has said about 200 million euros of damage has been carried out.

Voting rules

While New Caledonia has on three occasions rejected independence in referendums, the cause retains strong support among the Kanak people, whose ancestors have lived on the islands for thousands of years.

Colonised by France from the second half of the 19th century, it has special status with some local powers that have been transferred from Paris.

French lawmakers this week pushed forward plans to allow outsiders who moved to New Caledonia at least 10 years ago to vote in the territory's elections.

Pro-independence forces say that would dilute the vote of Kanaks, who make up about 40 percent of the population.

Voting reform must still be approved by a joint sitting of both houses of the French parliament.

President Emmanuel Macron has said French lawmakers will vote to adopt the constitutional change by the end of June unless New Caledonia's opposing sides can strike a new deal.

But a videoconference between Macron and New Caledonian lawmakers planned for Thursday was cancelled as "the different players did not want to speak to one another", his office said.