PARIS - Police killed two men during an overnight operation in the French territory of New Caledonia amid unrest between indigenous Kanaks and French loyalists, the Noumea prosecutor's office said on Thursday.

The killings raise to 13 the death toll on the Pacific island since the start of a crisis triggered by a controversial voting reform that was suspended in June.

The incident took place in Saint Louis, a stronghold of the independence movement south of Noumea, as police searched for about a dozen people suspected of involvement in armed robbery and attacks on security forces, according to the statement released by the police.

A gendarme opened fire after security forces were threatened by a group of armed individuals, killing two of them, it said.

The pro-independence FLNKS said the two were Kanaks.

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Kanaks fear the reform would dilute their vote and make it harder for any future referendum on independence to pass, while Paris has said the measure were needed to improve democracy by allowing more residents from France to vote.

In June, President Emmanuel Macron suspended the reform plan but violence has persisted in the territory, a major nickel producer.

Urban violence in Martinique

Separately, the prefect of France's overseas territory Martinique said on Wednesday he had imposed a nighttime curfew to limit movement in certain districts of Fort-de-France and Lamentin due to violence that has rocked the Caribbean island this month.

The curfew will run from Sept 18 to Sept 23 between 9 pm and 5 am and comes amid protests against the high cost of living, according to a statement.

READ MORE: Violent protests return as New Caledonia pro-independence leader extradited

Meanwhile, newly appointed French Prime Minister Michel Barnier, who was named on Sept 5 after two months of political chaos following snap legislatve elections, has yet to form his new government.