Niger's presidential election was "marred with a lot of irregularities and fraud," defeated opposition candidate Mahamane Ousmane said in an exclusive interview with DW.

Ruling party candidate and former foreign affairs minister Mohamed Bazoum was declared the winner of last Sunday's runoff vote with 55.75%.

He is also the hand-picked successor of outgoing President Mahamadou Issoufou, who is voluntarily stepping down after two five-year terms.

Ousmane garnered 44.25% according to Niger's Independent National Electoral Commission (CENI).

But the former president continues to slam the results as fraudulent.

"The results are marred by many irregularities and a lot of fraud… Our delegates had to point out these irregularities, but despite everything, CENI officials ignored them and went on to declare the results," Ousmane told DW on Saturday. He claimed that he narrowly won with 50.3% of the vote.

Ousmane said that "even though they said that these results were provisional," the election results should have been validated by various stakeholders within the CENI.

Polls opened for the second round of voting last Sunday after the 28 candidates in December’s vote failed to win an absolute majority.

Battling Jihadist insurgency

Ousmane became Niger's first democratically-elected president in 1993, only to be toppled in a coup three years later. February 21 marked Ousmane's fifth attempt to regain power since then.

The announcement of Niger's new leadership comes as the Sahel state continues to battle rising attacks by Islamic extremists.

For years, attacks by Jihadist insurgents have forced hundreds of thousands to flee their homes.

The West African country has also been declared the world's poorest according to the United Nations' benchmark of human development.

Elections trigger violence

Unrest broke out in Niger following the release of the presidential election results. Protests and clashes with police have occurred in several cities.

At least two people died in the post-election violence and the home of a Radio France Internationale (RFI) reporter in the capital Niamey was ransacked.

Deadly violence also struck the country on election day when seven CENI members were killed after their car hit an explosive device.

Leading Niger opposition figure Hama Amadou, who has been accused by the government of stoking the unrest, turned himself in to police in Niamey on Friday, according to one of his aides.

Hamadou had supported Ousmane during the election.

Referring to the violent unrest in recent days, Ousmane told DW, "How do you want them (citizens) not to be frustrated? From injustice comes frustration, and from frustration comes revolt."

According to the 71-year-old, the "undue arrests" of hundreds of people in Niamey have prompted widespread anger.

"Revolt creates insecurity. These arrests must stop," Ousmane said, adding that there have been 467 arrests in the capital.

Reactions from international community

France and several international bodies such as the UN have appealed for peace in Niger.

But Ousmane says there must be an end to arrests in order for there to be any stability.

"People are fed up. They simply want the expression of the popular vote to be reflected in these (election) results," he said.

Ousmane was interviewed by DW's Eric Topona.