Pro-independence, largely Indigenous protests against a French plan to impose new voting rules on its Pacific archipelago have spiralled into the deadliest violence since the 1980s, with a police officer among several killed by gunfire.

On major thoroughfares, the torched detritus amassed over four days of unrest was scattered amid fist-size hunks of rock and cement that appeared to have been flung during riots.

Armoured vehicles roved the city’s palm-lined boulevards, usually thronged with tourists.

EXPLAINED: Whats’ behind the violence on New Caledonia?

Fearful locals set up make-shift roadblocks – piling wooden pallets, wheelbarrows, bedframes, plastic jerricans, tree fronds and scraps of fencing across the streets.

As part of a sweeping French response, security forces placed five suspected ringleaders under house arrest, according to a statement by the high commission, which represents the French state in New Caledonia.

House searches will be carried out “in the coming hours”, it said.

More than 200 “rioters” have been arrested since the clashes broke out, the high commission said.

Hundreds of people, including 64 police, have been wounded, officials said.

French authorities reported a third night of “clashes”, though AFP correspondents in the streets of the capital Noumea said it appeared calmer than previous nights.

White residents in some neighbourhoods sat on garden chairs, manned barricades and strung up improvised white flags, a symbol of their intention to keep peaceful watch over the streets.

Onlookers ambled around the husks of burned-out shops, navigating twisted shutters, looted shelves and discarded packaging.

“We just grabbed what there was in the shops to eat. Soon there will be no more shops,” said one woman in a suburb of the capital, who spoke on condition of anonymity.

“We need milk for the children. I don’t see it as looting,” she told AFP.

France is establishing an “air bridge”, the high commission said, to rapidly move in troop and police reinforcements but also to bring in essential supplies for the population.

In Paris, French President Emmanuel Macron offered to hold talks on Thursday with New Caledonian lawmakers and called for a resumption of political dialogue.

French Prime Minister Gabriel Attal told a crisis ministerial meeting that troops had been deployed to secure ports and the international airport, which has been closed to commercial flights.

TikTok had been banned because it was being used by rioters, he said. By Thursday morning, AFP could identify fewer than 20 accounts related to the violence on the platform.

New Caledonia, which lies between Australia and Fiji, is one of several territories around the globe that remain largely under French control in the post-colonial era.

Colonised by France from the second half of the nineteen century, it has special status, unlike the country’s other overseas territories.

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

The state of emergency enables authorities to enforce travel bans, house arrests and searches.

Along with a night curfew, there are bans on gatherings, the carrying of weapons and the sale of alcohol.

Nearly 1,800 law enforcement officers have been mobilised and a further 500 will reinforce them, a French government spokeswoman said.

As people took to the streets, France’s National Assembly, 17,000 kilometres away, voted on Tuesday to allow residents who have lived in New Caledonia for 10 years to cast ballots. The reform must still be approved by a joint sitting of both houses of the French parliament.

Pro-independence forces say that would dilute the vote of Kanaks, who make up about 41 percent of the population.

But those favouring the reform argue voter lists have not been updated since 1998 – depriving island residents who arrived after of being able to participate in provincial polls.

Macron has said French lawmakers would vote to definitively adopt the constitutional change by the end of June unless New Caledonia’s opposing sides agree on a new text that “takes into account the progress made and everyone’s aspirations”.

Pro- and anti-independence parties issued a joint statement calling for “calm and reason” to return to the archipelago, adding that “we are destined to keep living together”.