Vote counting in Niger began Sunday night after presidential elections ended at 7.00 p.m local time.
Polls are however expected to reopen today at 8.00 a.m local time in areas where voting could not take place.
There were slight delays in the exercise due to late arrival of ballot papers in some polling stations.
Incumbent President Mahamadou Issoufou also contested in the polls in the hope of securing a second term in office.
According to critics, the president has used political repression in the run-up to the vote, arresting opposition supporters including his main rival Hama Amadou, currently behind bars for baby-trafficking charges, a case he has continuously denied.
President Issouffou faces 14 candidates including Seyni Oumaru, leader of an opposition coalition.
Security was tightened during Sundays vote, with results expected in the coming days.
Security forces patrolled cities and villages in case of unrest or militant attacks.
It is however reported that two electoral commission vehicles were attacked by unidentified armed men in a rural area about 100 km northwest of Niamey.
Niger has been under attack from Islamist militants Boko Haram based in neighbouring Nigeria.