Gunmen attacked a convoy of Canadian gold miner Semafo's employees in eastern Burkina Faso, killing at least 37 people and wounding 60 others.
The firm said the bloodshed happened near its Boungou mine and involved five buses of employees who were being accompanied by a military escort.
"Boungou mine site remains secured and our operations are not affected," Semafo said in its statement. "We are actively working with all levels of authorities to ensure the ongoing safety and security of our employees, contractors and suppliers."
This is the third deadliest on Semafo staff in 15 months.

US, German scientists win Nobel medicine prize for work on light and brain
Nigeria military aircraft crashes with 32 aboard
At least 22 dead after boats collide on Congo river
Spanish PM Sanchez calls snap election for November 29
Hundreds of French schools stay closed ahead of nationwide day of student protests