The UN-sponsored radio said the accident happened on Monday at Pangoy, 120 kilometres (75 miles) from Manbasa, as illegal miners rushed to be the first in the bottom of the pit. The sides collapsed, burying them all.
The local government chief confirmed the number of dead, the radio said. He added that the mine had been abandoned after clashes between the regular army and a militia headed up by Paul Sadala, alias Morgan.
The type of mine was not immediately known. Similar accidents are all too common in the east of this enormous nation, which is rich in minerals such as coltan, used in the making of electronic gadgets, and cassiterite, or tin ore.