Col. Saidou Sanou, the region's governor, gave the provisional toll in a statement, while the mining company only said that it was aware of "several fatalities and injuries".
The bus convoy of company employees, contractors and suppliers, escorted by military personnel, was attacked about 40 kilometres from the Boungou mine.
These groups are not the only ones accused of violence in Burkina Faso: so-called self-defence groups and the security forces have both been accused of committing human rights violations.
Boungou mine site remains secured, but the company have suspended operations out of respect to the victims and those impacted and to ensure the highest levels of operational safety.
The company blamed "armed bandits" for last year's attacks, and subsequently reinforced its armed escorts.
Burkina Faso's northern provinces have been battling a almost five-year wave of jihadist violence that came from neighbouring Mali.
Although the country witnessed its first extremist attack in the year 2015 and is a link south into the coastal part of West Africa.
Nearly 500,000 people have also been forced to flee their homes.
The nation's security forces have been unable to stem the violence, which has intensified throughout this year to become nearly daily.
The Sahel region, including Burkina Faso's neighbours Mali and Niger, has been afflicted by the violence despite the presence of the regional G5 Sahel force as well as French and USA troops.
Last year, African forces took part in a US -led counter-terrorism training program in Burkina Faso as part of an annual military exercise for West African nations.
Once peaceful, Burkina Faso has been suffering from a rapidly deteriorating security situation: since 2015 at least 500 people have been killed and almost half a million people are internally displaced. Then in August 2017, 18 people were killed in an attack on a Turkish restaurant in the capital.