Swiss mining company Glencore says seven people are missing following a landslide at a massive open pit copper mine in southeastern Congo owned by one of its subsidiaries.

Glencore said Katanga Mining Limited reported Tuesday that a "geotechnical failure" — or a landslide — had occurred on the north wall of the KOV open pit mine. A Glencore statement said search and rescue operations are underway for the seven people who were believed to have been working on the dewatering of the pit.

Katanga Mining said on its website that mine operations were suspended after the incident Tuesday morning. It said an assessment of the damage was also underway.

Katanga, about three-quarters owned by Glencore, says the KOV mine is "the largest high-grade copper resource in the world."