A convoy of buses came under attack on Wednesday as they were transporting workers of a Canadian mining firm on a road leading to the Boungou mine, in the country's eastern state of Borno, Presstv Reported.
Regional officials initially put the death toll at about 40, but a man, identified as Abel Kabore, who survived the attack told Reuters that “there were so many dead. It was over 100.”
A security source who works in the sector said that the convoy was likely carrying around 250 people.
Officials identified the bodies of 29 victims on Friday, said public prosecutor Harouna Yoda, but several are still missing.
“The three buses which were shot…We were on the ground. We saw everything,” Kabore was quoted by Reuters as saying while being treated at a hospital in the capital Ouagadougou.
He said the gunmen, speaking a foreign language, started shooting at three buses after a security vehicle escorting the convoy hit a landmine.
“The first two buses were able to escape,” he said, adding that of the people on his bus, "only 3 of us survived."
Another survivor said the gunmen fired at the bus for an hour, and then came aboard to execute survivors.
"I pretended I was dead — that was all I could do," he added.
Another wounded survivor described the scene of the attack, saying, “People were trying to go back into the buses. I tried to run away into the bush, and saw that they (the attackers) went back onto the buses, opened the doors and tried to kill everyone.”
Burkina Faso, a former French colony, has been plagued with violence for three year, since an insurgency began spreading into the nation from neighboring Mali in 2015.
Ever since, more than 500 people have died in attacks that have become increasingly violent, especially in the north and the east, AFP reported.
Outfits affiliated with al-Qaeda and the Daesh Takfiri terrorist groups have used central and northern Mali as a launch pad for growing numbers of attacks across the Sahel region, especially on neighbors Niger and Burkina Faso.