Five miners have been killed, two others injured and one is reported missing following a collapse at an abandoned quarry in southeastern Democratic Republic of Congo, a witness told AFP Monday.

The incident occurred on Saturday in Kolwezi, in the Katanga region, with the bodies of the five clandestine diggers retrieved on Sunday morning.

Three of the five victims were from the same family.

The group entered the disused quarry via a tunnel and were engulfed by the collapse of an embankment in the early afternoon.

They lay trapped at the base of the gallery for 12 hours before rescuers took the two survivors to Kolwezi hospital, the witness said.

Some 3000 people dig by hand at the old copper quarry, according to mining sector analysts.

In all, around 150 000 people scrape a meagre living by picking over disused mine workings for cobalt and copper throughout the entire Katanga province.

The practice is technically illegal, but authorities have for years allowed them to do so.

The pressure group Global Witness estimates the scavengers survive on less than three dollars (two euros) per day. Katanga is home to more than 30 percent of the world's estimated cobalt reserves and 10 percent of copper reserves. It also yields tin, gold and uranium.