Unidentified assailants on Sunday kidnapped three people working at a gold mine run by Ghana-based Balaji in northeastern Burkina Faso, near the border with Mali, a company official told Reuters on Monday.
The workers - one Burkinabe, one South African and one Indian - set off for the capital Ouagadougou from the remote Inata mine, about 200 km (125 miles) away, on Sunday morning before losing contact with colleagues, said a security officer at the mine who asked not to be named.
An official at Balaji Group told Reuters: "It is true that three people were kidnapped.
"The authorities are working on it but we don't have the details of that yet," he added, speaking on condition of anonymity.
The security officer said attempts to contact the workers had been in vain. He was unable to provide further details.
It was not clear who was responsible for the disappearance. Jihadist groups have become increasingly active in northern Burkina Faso in recent years, mirroring a wider proliferation in the arid Sahel region of jihadist groups with links to al Qaeda and Islamic State.
South Africa's International Relations and Cooperation Ministry said it was working with law enforcement on an "incident" but did not provide more detail.