It was the third deadly attack suffered by the Canadian firm Semafo in 15 months in the West African country, which is battling growing violence.
An attack on a convoy transporting local employees of Canadian mining company Semafo in Burkina Faso left 37 people dead and 60 wounded on Wednesday, a regional governor said.
It was the third deadly attack suffered by Semafo in 15 months in the West African country, which is battling a militant revolt that has claimed hundreds of lives.
Saidou Sanou, the governor of Est Region, said in a statement that the ambush by "unidentified armed individuals" took place on Wednesday morning.
The five buses escorted by the military were approximately 40 kilometres (25 miles) from the Boungou gold mine when they were ambushed, resulting in "several fatalities and injuries," mine owner Semafo said in a statement.
"We are actively working with all levels of authorities to ensure the ongoing safety and security of our employees, contractors and suppliers," Semafo said, while offering condolences to the families of the victims.
The mine itself, it added, remains secure and its operations had not been affected.
After similar attacks last year, Semafo said it would transport expat workers to its mine by helicopter.
Two deadly attacks last year
Semafo, which operates two mines in the Burkina Faso, was hit by two deadly attacks last year.
One in August 2018 also targeted vehicles travelling to its mines, and last December a police vehicle was ambushed on the same road between the city of Fada and the Bongou gold mine.
The company blamed "armed bandits" for last year's attacks, and subsequently reinforced its armed escorts.
Burkina Faso is an impoverished and politically fragile country in the Sahel region, and its security forces are badly equipped, poorly trained and underfunded.
The country's northern provinces have been battling a four-year-old wave of militant violence that came from neighbouring Mali.
The attacks -- typically hit-and-run raids on villages, road mines and suicide bombings -- have claimed more than 630 lives nationally, according to an AFP toll.
On Monday, an attack on a base in northern Burkina Faso killed at least five gendarmes and five civilians.
Nearly 500,000 people have also been forced to flee their homes.