The Pacific island of Bougainville is voting for its first ever autonomous government. The poll is being seen as a test for a UN-brokered peace deal, which ended over a decade of separatist fighting. The final day of polling is on 2 June.
What is the background?
Bougainville is the largest of the Solomon Islands and a province of Papua New Guinea (PNG).
The separatist struggle began in 1989. Many Bougainvilleans were angry at environmental damage from the Australian-owned Panguna copper mine and a lack of local benefit from mining revenue.
The Bougainville Revolutionary Army (BRA) fought against PNG forces and pro-government militias until the Bougainville Peace Agreement was signed in August 2001. Thousands were reported to have died.
The deal guaranteed a referendum on independence in 10-15 years, promised more autonomy in the interim, and set out a plan for weapons' disposal.
In December 2004, PNG's parliament approved a Bougainville constitution, laying the ground for elections.
What is at stake?
Voters will chose a president and 39 representatives - one for each of 33 constituencies, plus 6 others, two for each of Bougainville's three regions.
There are polling stations throughout PNG for Bougainvilleans to vote. Postal voting is also allowed. Ten international observers have been invited.
Who is standing?
There are five candidates for president:
John Momis. Resigned as Bougainville governor in April to contest the election. A former Catholic priest and an MP for 34 years. Served briefly as PNG's deputy prime minister in 1985. Acted as negotiator between PNG's government and Bougainville separatists. Wants the autonomous government to succeed. Heads the New Bougainville Party.
Joseph Kabui. A former leader of the Bougainville Revolutionary Army. Now says the peace process provides the most "practicable, viable option" for the island. President of the Bougainville People's Congress Party.
James Tanis: Currently Bougainville peace minister and vice-president of the Bougainville People's Congress Party. Launched the Bougainville Independence Movement in April. Reportedly offered the party leadership to rebel leader Francis Ona, in a bid to bring him into mainstream politics.
Rebel leader Francis Ona (in blue)
The other two are: Joel Banam, chairman of the Leitana Council of Elders, a pro-administration body during the fighting, and Bartholomew Kigina, from Buin in South Bougainville.
A total of 235 candidates will contest the 33 constituency seats in the House of Representatives.
Fifty-three are running for the six regional seats.
Are there security concerns?
One question is whether rebel leader Francis Ona will disrupt the polls.
Ona is the leader of the Me'ekamui Movement, a breakaway faction of the Bougainville Revolutionary Army. The faction boycotted the peace process.
He recently came out of hiding and maintains Bougainville is already an independent state, so elections are unnecessary. He has demanded the withdrawal of the Australian and PNG presence in Bougainville.
But there have been reports of splits in his group, with many of his followers choosing to endorse the peace process.
Reports also say the Me'ekamui Movement has given an assurance it will not disrupt polling.
Has there been trouble so far?
Youths burned electoral rolls in South Bougainville in March, in what has been widely seen as a local dispute rather than a bid to derail the election by the Me'ekamui faction.
Presidential hopeful Joseph Kabui and two legislative candidates from his party were held up by members of a rival party on Buka Island in early May. Local leaders condemned the "isolated incident" and apologised.
The head of the UN observer mission, Tor Stenbock, has warned that a failure to comply with the weapons disposal schedule could jeopardize the election process.
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