"At the moment we have over 200 dead, some of them are still in the mud and have not been recovered yet," said Lumumba Kambere Muyisa, spokesperson for the governor of North Kivu province.
He said the landslide at the Rubaya mines was triggered by heavy rains.
The mining area, like the province of North Kivu, is held by the Rwandan-backed rebel group M23.
The Rubaya mines produce coltan, a raw material usually classed as "conflict minerals." This is because the high global demand creates conflicts between militia groups that control many of the mines.
Coltan is the ore used to extract tantalum, a key metal in the manufacture of mobile phones and many other electronic devices.
