The death toll in an attack on villages in southwestern Niger has risen to at least 137 people, a government spokesman said Monday.

The attack constitutes the deadliest suspected jihadi massacre to hit the African nation in recent times.

"In treating civilian populations systematically as targets now, these armed bandits have gone a step further into horror and brutality," government spokesman Zakaria Abdourahamane said in a statement on public television.

The government has revised the death toll of the attack, which was previously estimated to be 60.

What happened in the attack in Niger?

Armed men on motorbikes struck the villages of Intazayene, Bakorat and Wistane near the border with Mali, shooting "at everything which moved," a local official said.

"The government condemns these brutal acts perpetrated by individuals who know neither faith nor the law," the government spokesman said.

He also announced three days of national mourning starting Tuesday, adding that the government vowed to reinforce security in the region and bring "the perpetrators of these cowardly and criminal acts" to justice.

Rising extremist attacks

The massacre comes amid an escalation in attacks following the election of President Mohamed Bazoum in late February. His election was confirmed by the country's constitutional court on Sunday.

Last week, 66 people were killed in a similar attack in the Tillaberi region, a "tri-border area" where the frontiers of Burkina Faso, Niger and Mali converge.

President Bazoum offered his condolences to the family of the victims in a tweet on Monday, calling out the "barbaric way" in which the "terrorists struck the peaceful civilian populations."

The attack also brought back memories of a January massacre that left 100 people dead in two villages in the Mangaize district of Tillaberi.

The region is plagued by jihadi activity which, according to analysts, is made worse by counterterrorism offensives that help give rise to ethnic militias.

Niger is battling the spread of deadly extremist violence, with jihadi insurgencies that have spilled over from Mali and Nigeria.

adi/rt (AFP, AP)