Guinea-Bissau's main opposition leader, Kumba Yalla, is confident of winning the presidential run-off vote that will restore democracy to the West African nation after a military coup.

"I am confident - I will beat my opponent Malam Bacai Sanha," he said as he voted in Quinhamel, 40km north of the capital.

Preliminary results are expected on Tuesday at the earliest.

Sunday's election in the former Portuguese colony will wrap up a transition brokered after the army revolted against then President Joao Bernardo Vieira in 1998.

First round winner

Mr Yalla, of the Party for Social Renewal, went into Sunday's run-off with the support of some of his first round rivals.

The one-time Marxist professor of philosophy had won 38.8% of the vote in the 28 November round, compared to caretaker President Sanha's 23.4%.

Mr Sanha is the candidate of the African Party for the Independence of Guinea and Cape Verde (PAIGC), the former ruling party in one of the world's poorest countries.

Heavy turn-out

Reports from Guinea-Bissau said there had been a high turnout of voters. The reports said polling went smoothly after booths opened on time around the country.

A strike threat over pay by some electoral officials had threatened to complicate polling - the officials said they were owed money for earlier work, and threatened to boycott the run-off.

The transitional Prime Minister, Francisco Fadul, assured officials they would be paid, and warned that anyone disrupting the election would be prosecuted.

Polling in the first round was hit by serious logistical delays, and in some remote areas it went into a second and even a third day.

But the United Nations Security Council hailed the poll itself as "open, fair and transparent".