Voters in Niger are to go the polls in the country's presidential and parliamentary elections.
President Mahamadou Issoufou is hoping to secure a second term in the impoverished West African nation.
The run-up to the vote has been marred by accusations of repression and a row over identification documents.
The authorities have announced that roughly 1.5 million people without ID papers will be able to cast their ballots by having witnesses vouch for them, in a move that was condemned by opposition leaders.
Crowded field
Polling stations are due to open at about 08:00 local time (07:00 GMT) on Sunday.
Meanwhile President Issoufou says his government foiled a coup plot in December.
One of the candidates in Sunday's presidential election, Ibrahim Hamidou, was arrested for casting doubt upon December's alleged coup but was released in January against the wishes of state prosecutors.
Well-known figures among the crowded field of 15 presidential candidates also include former Prime Minister Hama Amadou, who denies trafficking babies from neighbouring Nigeria, and Mahamane Ousmane, Niger's first democratically elected president.
A run-off will be held if no candidate secures an outright victory on Sunday.
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