Armed men have killed around 100 people in an attack on a village in the north of Burkina Faso, President Roch Kabore has said.
During the overnight raid on Solhan, homes and the market were also burned, Reuters news agency reports quoting a government statement.
No group has said it was behind the violence.
But Islamist attacks are increasingly common in the country, especially in regions bordering Niger and Mali.
President Kabore has declared three days of national mourning saying, in a tweet, that “we must stand united against the forces of evil”.
The security forces are currently looking for the perpetrators, he added.
In another attack on Friday night, 14 people were reported to have been killed in the village of Tadaryat, about 150km (93 miles) to the north of Solhan.
Last month, 30 people died in an attack in the east of Burkina Faso.
The country is facing a deepening security crisis, like many of its neighbors, as armed groups carry out raids and kidnappings across much of the region.
In May, the Burkinabe army launched a large-scale operation in response to a resurgence of militant attacks. Despite this, the security forces are struggling to prevent the violence that has forced more than a million people from their homes over the past two years.
Africa’s semi-arid Sahel region has been hit by an insurgency since militants captured large parts of northern Mali in 2012 and 2013.
French forces have been supporting troops from Mali, Chad, Mauritania, Niger, and Burkina Faso to fight the militants.