In this file photo taken on November 11, 2019, an Armoured Personnel Carrier (APC) of the French Army patrols a rural area during the Bourgou IV operation in northern Burkina Faso along the border with Mali and Niger. (MICHELE CATTANI / AFP)

OUAGADOUGOU－The death toll from a massacre of civilians in Burkina Faso's volatile north has climbed to more than 160, local officials said on Sunday, and around 20 children were killed in the deadliest attack since extremist violence erupted in the West African country in 2015.

The slaughter in the early hours of Saturday followed the slaying of 14 people late on Friday in the village of Tadaryat in the same region, where extremists linked to the al-Qaida and Islamic State terror groups have been targeting civilians and soldiers.

In Solhan, in the region near the borders of Mali and Niger, local sources said they have recovered 160 bodies from three mass graves.

Burkina Faso's President Roch Marc Christian Kabore on Saturday condemned the massacre in Solhan as "barbaric" and "despicable".

"We must remain united and solid against these obscurantist forces," Kabore said.

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Declaring three days of national mourning through Monday, the government stated that "terrorists", a term for extremists, killed civilians of all ages and set fire to homes and the main market.

United Nations Secretary-General Antonio Guterres was "outraged "over the massacre, his spokesman Stephane Dujarric said.

Guterres "strongly condemns the heinous attack and underscores the urgent need for the international community to redouble support to member states in the fight against violent extremism and its unacceptable human toll", Dujarric said in a statement, offering Burkina Faso authorities the UN's "full support".

Solidarity from Paris

Meanwhile, French Foreign Minister Jean-Yves Le Drian said he would visit the former French colony this week, saying he would reiterate Paris's solidarity after speaking with Kabore by phone.

The assailants struck around 2 am local time against a position of the Volunteers for the Defence of the Motherland, or VDP, an anti-extremist civilian defense force which backs the national army, before attacking homes and carrying out "executions", a local source said.

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Opposition leader Eddie Komboigo demanded that "the massacre of our people, we never tire of repeating, must stop unconditionally. Every measure must be taken to protect the Burkinabe" people.

The VDP was set up in December 2019 to help Burkina Faso's military fight extremists but it has suffered more than 200 fatalities, according to an Agence France-Presse tally.

The volunteers are given two weeks' military training before working alongside the security forces, typically carrying out surveillance, information-gathering or escort duties.

The government said on Saturday that the defense and security forces were working "to neutralize these terrorists and restore calm to populated areas".