Hundreds more security personnel will join the 1,500 reinforcements already on the ground in New Caledonia after the worst unrest in the French Pacific territory in more than 30 years.

The High Commission of New Caledonia, which represents the French state in the territory, said on Tuesday that 600 personnel would be deployed in the coming hours to join those already sent from France.

“The return to calm continues throughout the territory,” it said in a statement, but added that the airport in the capital, Noumea, would remain closed to commercial flights, with the situation to be reviewed on Thursday.

The government has said about 3,200 people were waiting to leave or enter New Caledonia when flights were cancelled last week when violence broke out over French plans to amend voting laws to allow more recent arrivals to vote in provincial elections.

Six people were killed after makeshift blockades were set up on Noumea’s streets, cars and businesses set on fire and shops looted. The high commission said efforts were under way to clear the remaining barriers and remove the burned-out vehicles and other debris.

Australia and New Zealand, meanwhile, sent their first military planes to New Caledonia to evacuate their nationals.

An Australian C-130 Hercules aircraft landed at Noumea’s Magenta airport, which usually handles domestic traffic, on Tuesday afternoon, the AFP news agency reported.

“Passengers are being prioritised based on need. We continue to work on further flights,” Australian Foreign Minister Penny Wong said on social media, announcing two initial flights.

New Zealand’s Foreign Minister Winston Peters, meanwhile, said the first military aircraft would repatriate “50 passengers with the most pressing needs” to Auckland. He said more flights were scheduled for the coming days.

The civil disturbances are the worst in the territory of some 270,000 people since the 1980s and reflect concerns among the Indigenous Kanak community, who make up about 40 percent of the population, that changes to the electoral system will dilute their vote and political influence.

The voting system for provincial elections was established in the 1998 Noumea Accord, a result of the previous unrest, and excluded later European arrivals from France. Under the new constitutional amendment, those who have lived in New Caledonia for at least 10 years will get a vote.

Viro Xulue, part of a community group providing social assistance to other Kanak amid the crisis, said it felt like a return to the civil war of the 1980s, and people were scared.

“We are really scared about the police, the French soldiers, and we are scared about the anti-Kanak militia terrorist group,” Xulue told the Reuters news agency in a video interview.

Three of the six people killed in the unrest were young Kanak and were shot by armed civilians. There have also been confrontations between Kanak protesters and armed self-defence groups or civilian militias formed to protect themselves, France’s High Commission said previously.

French officials said at the weekend that security forces had dismantled 76 barricades set up along the 60km (40-mile) road from Noumea to the international airport, but AFP reported some had been rebuilt.

One was being manned by a group of masked Kanak people, some of whom were carrying home-made catapults.

A masked 25-year-old with sunglasses who gave only his first name Stanley told AFP that the proposed voting reform meant “the elimination of the Kanak people”.

“That’s what they don’t understand over there – we are already in the minority in our own home,” he said.