Niger began counting the votes Sunday from an election that is expected to lead to the West African nation's first transfer of power between two democratically elected presidents.

The voting process went on smoothly on Sunday and were no reports of widespread disruptions.

The West African country, unstable since gaining independence from France 60 years ago, is ranked the world's poorest country according to the UN's Human Development Index.

Around 7.4 million people were registered to vote in the presidential ballot, which coincided with legislative polls.

"I expect the Nigerien president to put security, health, progress and democracy first," Aboubakar Saleh, a 37-year-old launderer, told AFP in the capital Niamey without revealing his choice among the 30 candidates.

Issaka Soumana, a 52-year-old lorry driver, said he wanted change.

"Niger is not moving forward. Our country must rise," he said, brandishing his ink-stained thumb to show he had cast his ballot.

President Mahamadou Issoufou, who was elected in 2011 after the country's last coup in 2010, is voluntarily stepping down after two five-year terms.

"It is a special day for Niger which will experience for the first time in its history a democratic transition," Issoufou, 68, said after voting at the Niamey city hall.

He noted that Sunday's vote was the first in which he did not take part in three decades in the predominantly Muslim country.

At some polling stations in Niamey, voters saw to it that men and women formed separate queues to vote.

The frontrunner is Issoufou's designated successor, Mohamed Bazoum, 60, a former interior and foreign minister.

"It is a great source of pride that this date of December 27 has been respected," Bazoum said after voting.

He campaigned on promises of emphasising security and education, especially for young girls in a country with the world's highest fertility rate -- 7.6 children per woman.