The Malian army had no authorisation to cross into Burkina Faso and kill three people during a spate of ethnic violence last week government said.
Malian officials were not available to comment, but the Malian army said it pursued armed assailants into Burkina Faso.
Under a joint military taskforce called G5 Sahel, which includes forces from five West African countries, including Mali and Burkina Faso, army units can pursue militants up to 50 km into a member country’s territory.
Two years after G5 Sahel conducted its first operation members struggle to co-ordinate campaigns against jihadist and other armed militias who ghost over the long, unpoliced borders in the arid Sahel region south of the Sahara.
Instead, attacks by jihadist militias, some with links to al Qaeda or Islamic State, and ethnic violence proliferate, scuppering former colonial power France’s plans to wind down its nearly six-year military intervention in the region.
According to a letter addressed by Burkina Faso’s defence minister to his Malian counterpart and confirmed by the Burkinabe defence ministry, Malian forces crossed the border on Saturday after Burkinabe village Dozo hunters were attacked by Fulani herders from Mali.
In the village Malian forces encountered Dozo hunters mobilised to defend themselves against Fulani herders, the letter said.
“Malian soldiers proceeded to repress the population of Abaye leading to three deaths, including one crushed by the wheels of vehicles,” the letter said, adding several villagers were reportedly arrested and taken to Mali.
“The co-ordination mechanisms along our common borders were not activated by our Malian neighbours,” it said.
In a statement the Mali army provided a different version of events, saying men dressed as Dozo hunters first attacked a Fulani village in Mali and soldiers then pursued the hunters across the border.
There, it said, soldiers “dismantled” the assailants’ base, killing 10 and arresting 20.
Ethnic reprisal attacks killed hundreds of civilians in the two countries this year.