The people of a remote South Pacific island group have overwhelmingly backed independence from Papua New Guinea in a referendum.

Almost 98 per cent of voters in Bougainville cast their ballots in favour of creating the world’s newest country by breaking away from the state it has been part of since 1975.

Voters in the island group - sandwiched between Papua New Guinea and the Solomon Islands - were given the choice between further autonomy from the central government or complete independence.

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However, in a result that defied polling, more than 176,000 out of the 181,000 who went to the polls opted to create the world’s first internationally recognised ‘new’ country since South Sudan in 2011.

The Papua New Guinea government approved the referendum after years of conflict resulting from a bloody seven-year war between 1988 and 1997 over economic disputes.

The Herald: Bougainville is located between Papua New Guinea and the Solomon IslandsBougainville is located between Papua New Guinea and the Solomon Islands

The island group was once a rich source of copper mining, however large-scale extraction under Australian rule in the 1960s meant much of the resource was depleted.

The distribution of revenue from the practice was one of the reasons for the conflict.

The results were announced in the town of Buka by former Irish Prime Minister Bertie Ahern - chairman of the Bougainville Referendum Commission.

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"Now, at least psychologically, we feel liberated," said John Momis, president of the regional autonomous government told the AFP news agency.

One Bougainvillian, nursing graduate Alexia Baria, added that "happiness was an understatement" in response to the vote.

However, the referendum was not legally-binding and it remains to be seen whether the Papua New Guinea government will uphold the result.