“The toll has grown to 43,” Richard Muyej, governor of Lualaba province, where the accident took place, told dpa.
On Thursday authorities had recovered 36 bodies after the accident at the Kamoto Copper Company mine.
The miners were there illegally, according to the governor.
Congo is rich in minerals like copper and cobalt and accidents in mines are not uncommon.
News Agency of Nigeria recalls that in March, fourteen people were killed overnight when a small-scale mine in a tin-rich area of eastern DR Congo collapsed.
Local officials had said that the incident occurred in Niyabibwe, about 100 kilometres (60 miles) north of Bukavu, the capital of South Kivu province.
Miners had dug a shaft to look for cassiterite, a source of tin, but the walls caved in after heavy rain. “The search for survivors began at around 3 am and is ongoing,” senior administrative official Muhima Kateete told AFP.
“Fourteen bodies have been recovered, and there are nine injured,” he said.
Delphin Birimbi, head of a local association of NGOs, said the toll was provisional. Nine people are in hospital for serious injuries, a health worker said.
(Edited by Emmanuel Yashim)