MONTREAL -- An attack on employees of Quebec gold producer Semafo Inc. in Burkina Faso has left 37 people dead and 60 injured.

The attack occurred about 40 kilometres from the Boungou mine -- one of the two sites operated by the company in the West African country -- when a convoy of five buses accompanied by a military escort was ambushed.

The military vehicle ahead was reported to have struck an explosive device. The rest of the convoy was then shot by "unidentified armed individuals," according to a statement signed by the governor of the eastern region, Col. Saidou Sanou.

"A search by the defence and security forces is underway in the area," he said.

Semafo said in a statement that the Boungou mine site "remains safe and our operations have not been affected."

"We are working actively with all concerned authorities to ensure the health and safety of our employees, contractors and suppliers."

Nobody was available at the company's site in Africa in the late afternoon to provide further details. The origin of the victims was unknown. For several years Burkina Faso has been the scene of violent attacks attributed to jihadist fighters.

Based in Montreal, Semafo, which has 1,200 employees, including 85 expatriates at its Mana and Boungou sites. It had previously faced security challenges on roads leading to its facilities. That prompted the mining company to take additional measures to ensure the safety of its personnel, such as transporting its non-local employees by helicopter.

"So far, we do not have reports of Canadian citizens affected by the incident," Global Affairs Canada spokeswoman Angela Savard wrote in an email to The Canadian Press.

In August 2018, a Semafo employee and a subcontractor were killed when a bus carrying workers was targeted by bandits and five police officers were killed in another attack a few days earlier.

In December 2018 the gold producer reported that government security forces had been attacked on a road about 40 kilometres from the Boungou mine, resulting in five deaths.

Semafo is not the only Canadian mining company operating in Burkina Faso. Iamgold Corp. and Roxgold Inc. employ 2,200 and 800 employees in the country, respectively.

On the Toronto Stock Exchange, Semafo shares dropped 44 cents, or about 11 per cent, to close at $3.49.

This report by The Canadian Press was first published Nov. 6, 2019.