By Stanis Bujakera and Aaron Ross
KINSHASA (Reuters) - At least 39 artisanal miners were killed on Thursday when part of a copper and cobalt mine owned by Glencore (L:GLEN) collapsed in southeast Congo, the provincial governor said.
The accident occurred in the KOV open-pit mine at the Kamoto Copper Company (KCC) concession, in which Glencore subsidiary Katanga Mining (TO:KAT) owns a 75% stake, said Richard Muyej, the governor of Democratic Republic of Congo's Lualaba province.
"It was caused by the clandestine artisanal diggers who have infiltrated (the mine)," he told Reuters. "The old terraces gave way, causing significant amounts of material to fall."
"KOV is a delicate site and presents many risks," he added.
Glencore said in a statement that it had confirmed 19 fatalities so far and was assisting search and rescue operations by local authorities. The incident has not impacted production, it added.
The KOV mine, which spans a vast flat expanse on the outskirts of the city of Kolwezi near the Zambian border, is one of the largest high-grade copper assets in the world.
The collapse of a 250-metre wall inside the same pit killed seven mine employees in 2016.
Thousands of illegal miners operate in and around mines in southern Congo, which produce more than half of the world's cobalt, a key component in electric car batteries.
The often old or simple practices employed by artisanal miners can compromise the safety of the mines, and accidents are common.
Mine disasters in Africa have cost the lives of numerous miners, especially unauthorised artisanal miners who operate without safety standards or regulations.
At least nine illegal gold miners died in Zimbabwe when they were trapped in a mine last month.
Twenty-two died in a previous Zimbabwean gold-mine flood in February, and 14 tin miners were buried alive in Rwanda after heavy rains in January.
In February, about 20 people died when a truck carrying acid to Glencore's Mutanda Mine in DRC collided with two other vehicles.
Congo's military deployed hundreds of soldiers last week to protect a copper and cobalt mine owned by China Molybdenum Co Ltd (SS:603993) from illegal miners.
Shares in Glencore were down 4.9% by 1625 GMT, on track for their worst day of trading since July 2018.
"If this is related to illegal mining then the impact to production may be relatively short-term beyond an investigative period," said BMO Capital Markets analyst Edward Sterck.
"However, preventative action will likely be needed and it could impact Glencore's social licence to operate."