Niger voted in a presidential run-off election on Sunday, which incumbent President Mahamadou Issoufou is expected to win after his imprisoned opponent left the country for health issues and the opposition coalition calls for a boycott against the election.
Incumbent President Issoufou won the first round comfortably last month, with 48 percent of votes, but failed to secure the outright majority required to avoid a second round.
Polls officially opened at 7am (0700 GMT), but there were only a few early voters visible outside polling stations in the capital Niamey.
"I am against any boycott. I've just voted," said Sadou Ide, who cast his ballot at the Nogare School, in Niamey.
Security forces were deployed at polling stations. They also patrolled the streets of Niamey and monitored the city's main intersections.
The regional governor of Niamey, Hamidou Garda, issued a ban on gatherings outside polling stations for security reasons, late on Saturday.
"All gathering is forbidden. Voters come, vote and then leave," he said on state-owned television.
On Friday, the Coalition for an Alternative (COPA), which unites about 20 political parties including Amadou's MODEN, called for a boycott of the polls claiming the process had been covered by fraud.
Issoufou's supporters called the boycott "absurd" and urged all Nigeriens to go out and vote.
Hama Amadou a former president of parliament speaker finished second to Issoufou with 18 percent in the first round of polling last month.
He was accused of having connections to a baby-trafficking scandal in November, but denies the charges against him and says they are politically motivated.
His supporters claim he has suffered from ill health, during the time he has been jailed, in the town of Filingue, around 180 km (112 miles) northeast of the capital Niamey.
In April 2011, President Issoufou was elected into office following a popular coup that toppled previous leader Tandja Mamadou. He is seeking for a second five-year term to lead the impoverished uranium producer.