Thursday's accident occurred in the KOV open-pit mine at the Kamoto Copper Company (KCC) concession near Democratic Republic of Congo's southern border with Zambia, in which Glencore subsidiary Katanga Mining has a 75% stake.

The death toll was originally estimated at 36 but rose to 43 on Friday as more bodies were uncovered.

"We think that other bodies are still under the rubble," said Joseph Yav Katshung, the chief of staff to the governor of the Lualaba province where the incident occurred.

Lualaba Governor Richard Muyej said the army would deploy around KCC "for a limited time" to deter artisanal miners from entering, a move human rights activists said could stoke tension and lead to clashes.

Hundreds of soldiers were sent last week to a mine owned by China Molybdenum Co in response to the presence of as many as 10,000 informal miners there.

Officials said the miners caught up in the landslide at the KCC facility were on the site illegally without approval or permits, a common occurrence in Congo and across Africa.

Old-fashioned and unregulated mining methods, which can compromise safety, cost dozens of lives a year in Congo alone.

A union official representing KCC employees said a crack in part of the pit had been noticed on Wednesday. He said KCC had put up red warning signs, but the diggers had ignored them.

Glencore confirm 19 fatalities on Thursday and said it was assisting search and rescue operations by local authorities.

(Reporting By Fiston Mahamba in Kinshasa and Aaron Ross in Dakar; Writing by Edward McAllister; Editing by Edmund Blair)