Picture: Gerd Altmann/Pixabay

At least ten people were killed and dozens more are wounded and missing after an attack on a convoy transporting workers of Canadian gold miner Semafo in eastern Burkina Faso, three sources said on Wednesday.

Parts of Burkina Faso have been overrun by Islamist violence in the last years that the military has been unable to contain and Semafo tightened its security last year following armed incidents near two of its mines in the country.

Semafo said in a statement earlier on Wednesday that the attack took place between its Fada and Boungou mine sites, about 40 kilometres from Boungou, and that there were several fatalities and injuries.

Two security sources and a diplomatic source said later ten were killed.

The security sources said the military escort vehicle leading the convoy was struck by an IED on a stretch of road where there is no cellphone network.

Shortly after the initial explosion, an unknown number of gunmen opened fire on the convoy. One of the sources said that it appeared that they targeted the buses as well as the military escort, which was unusual.

In December a police vehicle was attacked on the same road, resulting in five deaths.

When contacted by Reuters about the latest attack, a Semafo spokeswoman said: "At this point, we do not have full information and are not in a position to add to this morning's release."

The Boungou mine is secure and operations are not affected, the company said.

Its Toronto-listed shares hit a nine-month low after the news and were trading down 10% by 1755 GMT.

Once a pocket of relative calm in the Sahel, Burkina has suffered a homegrown insurgency for the past three years, which has been amplified by a spillover of jihadist violence and criminality from its chaotic neighbour Mali.

After last year's incidents, which Semafo said were perpetrated by "armed bandits", the company reinforced its escorts and decided to transport all expatriate employees by helicopter between the Boungou mine and Ouagadougou.