At least four people died this week in mudslides at two informal mines in mineral-rich Guinea, where thousands risk their lives working in illegal pits, officials and witnesses said on Thursday.
The work becomes even more dangerous in the current rainy season.
The accidents occurred on Sunday and Wednesday in the mines of Kintinian in the extreme north-east. The dead include a woman.
Guinea has gold, diamonds, bauxite and prodigious reserves of iron ore. Illegal miners include locals and also nationals from nearby countries such as Burkina Faso, Liberia and Ivory Coast.
Authorities say there are more than 20 000 such miners in the Siguiri region where Kintinian is located.
Aliou Guisse, the sub-prefect of Kintinian, said he had issued repeated warnings to stop illegal mining during the monsoons, which can trigger mudslides.
"Despite incessant appeals ... there are still many who go to these mines to find gold at the risk of their lives," he told AFP.
A guard at a local mine said illegal miners often sneak into water-filled galleries to "mine without any restraint".