France ordered troops to guard ports and the international airport in its Pacific territory of New Caledonia as a state of emergency started Thursday after two nights of riots left four dead and hundreds wounded.

Turmoil erupted after France's national assembly backed hotly-disputed changes to voting rolls that indigenous Kanak leaders say will dilute their vote.

The use of security forces and the ordering of a night-time curfew has failed to halt the worst violence seen in New Caledonia since the 1980s.

Shops have been looted and public buildings torched during night-time violence. Hundreds of people including around 100 police and gendarmes have been injured, French Interior Minister Gerald Darmanin said.

The presidency said three people, including a gendarme, had been killed. 

New Caledonia, which lies between Australia and Fiji, is one of several territories around the globe that remain part of France in the post-colonial era. Colonised by France from the second half of the nineteenth 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 indigenous Kanak people.

President Emmanuel Macron called for a resumption of political dialogue, the Elysee said. But the government approved a state of emergency from Thursday morning local time, spokeswoman Prisca Thevenot said. 

Prime Minister Gabriel Attal told a crisis ministerial meeting that troops had been deployed to secure ports and the international airport and the government representative in New Caledonia has "banned TikTok". 

The airport is already closed to international flights. Attal said the situation in New Caledonia was now "grave" but that the government priority was to "restore calm" so that a dialogue could be established.

Under the state of emergency, authorities will be able to enforce travel bans, house arrests and searches, Thevenot added.

Sources said that two radical pro-independence activists had been put under house arrest.

Nearly 1,800 law enforcement officers have been mobilised and a further 500 will reinforce them, she added.

Macron cancelled a planned trip to Normandy to chair a new emergency meeting on Thursday, the presidency said. 

- Looting and fires -              

In Noumea and the commune of Paita there were reports of gun battles between civil defence groups and rioters.

Streets in the capital were pocked with the shells of burned-out cars and buildings, including a sports store and a large concrete climbing wall.

"Numerous arsons and pillaging of shops, infrastructure and public buildings -- including primary and secondary schools -- were carried out," said the government in the territory.

Security forces had regained control of Noumea's prison, which holds about 50 inmates, after an uprising and escape bid by prisoners, it said in a statement.

Police have arrested more than 130 people since Monday night, with dozens set to face court hearings, the commission said.

A nighttime curfew was extended, along with bans on gatherings, the carrying of weapons and the sale of alcohol.

As rioters took to the streets, France's lower house of parliament 17,000 kilometres (10,600 miles) away voted to give a vote to people who have lived in New Caledonia for 10 years. 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, the Indigenous group that makes 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 since then from mainland France or elsewhere of a vote 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".