Mauritanians are voting in the first presidential elections since a military coup two years ago.

With no clear favourite among the 19 candidates, including former ministers, a run-off looks likely.

Mauritania is home to a number of different racial groups and many people are likely to vote along ethnic lines.

The army leader, who is stepping down, says for the first time Mauritanians will elect "in a free and transparent manner, without state interference".

Colonel Ely Ould Mohamed Vall, whose military council took power in a coup in August 2005, said that the polls will mark the moment when Mauritanians "come of age".

"The campaign went by in absolute calm and without the slightest of incidents," he said in a pre-election interview.

Keeping the military out of power is seen as a key issue for a country which has seen a number of coups since independence.

Before the coup, Mauritania spent 21 years under the iron grip of former President Ahmed Taya and elections in those days were regarded as a sham, reports the BBC's Richard Hamilton from the capital, Nouakchott.

Among the candidates, three are tipped to do well:

·                          Sidi Ould Cheikh Abdellahi - a former minister and economist

·                          Ahmed Ould Daddah - half-brother of the country's first post-independence leader

·                          Zeine Ould Zeidane - former central bank governor.

Unity

Another key issue for the nation is how to unite an ethnically diverse population, which includes Arabs, Berbers and sub-Saharan Africans, our reporter says.

While many presidential hopefuls come from the ruling Arab elite, one candidate represents descendants of slaves.

Despite a ban on slavery in 1980, human rights groups say the phenomenon still exists in the country.

But many are reluctant to openly discuss these issues.

"I don't consider we have a problem of national unity, these are social problems that exist everywhere," said Colonel Vall. Other major campaign issues have been how to manage the country's new oil reserves and the Islamic republic's decision to recognise Israel

In February last year, Mauritania started pumping millions of barrels of oil from offshore reserves, though people have still to see any benefits.

In 1999, Mauritania hit the headlines when it became one of only three Arab nations to recognise Israel.

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BBC