"Following an anti-terrorist operation waged for days in Kossi (province), GARSI (Burkina Faso's rapid intervention force), an assault was launched on Tuesday against two terrorist bases in the town of Wariberi," the army said in a statement.

"This surprise attack caused huge losses on the enemy side," with 47 fighters dead, it said, adding that the army destroyed or seized "large quantities" of materiel.

Two gendarmes died and another three were wounded in the operation, it said.

The figures could not be independently verified.

On Monday, two soldiers and five civilian defence volunteers were killed during an ambush on a military patrol in the north.

The attack was claimed by the Group to Support Islam and Muslims (GSIM), the main jihadist formation in the Sahel region allied with Al-Qaeda.

On May 11, jihadists killed eight Burkinabe soldiers during an attack close to the Niger border in Yagha province, security sources said at the time.

Burkina Faso is part of a regional effort to battle an Islamist insurgency, along with neighbouring Mali and Niger, Mauritania and Chad.

However, the West African country's under-equipped and poorly trained military has been unable to stem the violence despite help from France, which has 5,000 troops in the Sahel.

According to UN figures, jihadist attacks in Burkina Faso, Mali and Niger left nearly 4,000 people dead last year. Some 800,000 people have been displaced since 2015.