Voters in the Central Asian country of Kyrgyzstan are casting their ballots in a presidential election that could set a democratic precedent for the region.

Almazbek Atambayev, the current prime minister, is up against two popular nationalist politicians, Kamchibek Tashiyev and Adakhan Madumarov, as well as 13 other candidates in Sunday's contest.

Roza Otunbayeva, the outgoing president who has been running the country as interim leader since 2010, will be stepping down to make way for her successor.

The election is the first presidential contest since Kurmanbek Bakiyev was forced out of office by an uprising in April 2010 and marks the culmination of a movement for political reform away from the strong authoritarian model that has prevailed in the country since independence from Moscow in 1991.

Candidates need to gain more than 50 per cent of the vote to be elected on Sunday. Otherwise, the process will go to a second round between the first- and second-placed candidates within a month.

Atambayev, whose well funded campaign has enjoyed significant public exposure, has said he is confident the contest will be settled in one round.

'Bright hopes'

"I have bright hopes; it is time for our country to live, achieve harmony and flourish. People are tired of political battles and meetings,'' he told the AP news agency.

Al Jazeera's Robin Forestier-Walker reporting from Bishkek, the Kyrgyz capital, said: "Independent polls have put Almazbek Atambayev in the lead, but there could be a run-off against Adakha Madumarov who is expected to finish second."

Kyrgyzstan, a former Soviet nation of five million on China's western fringes, is home to both US and Russian military air bases, making its fortunes the subject of lively international interest.

Madumarov and Tashiyev have repeatedly levelled accusations of possible vote-rigging ahead of the election.

"The main thing is that there should be no evidence of fraud and the election results must not be falsified," said Tashiyev.

Nearly 400 international observers from 41 countries have been deployed to monitor Sunday's vote, according to the Organisation for Security and Co-operation in Europe.

While the election has been hailed by many as a victory for democracy, many are concerned that the vote could lay bare regional and ethnic divisions. Atambayev’s following is mainly in the north, while his nationalist opponents’ main base of support is in the south.

Southern Kyrgyzstan, which lies along a major route for heroin trafficked northward from nearby Afghanistan, has seen waves of political unrest over the past year and was the site of ethnic clashes last summer in which hundreds of people, mainly minority ethnic Uzbeks, were killed.

Source: Al Jazeera and agencies