At least 200 artisanal miners died Tuesday when hand-dug tunnels collapsed at the Rubaya coltan mine in eastern Democratic Republic of Congo, the Congolese Ministry of Mines said — the second mass-casualty collapse at the rebel-controlled site in less than two months. Rebels and government spokespeople disputed both the death toll and the cause. The Rwandan-backed M23 rebel group has controlled the mine since May 2024.
Researchers say the loss of state services and civil-society oversight since M23’s takeover has worsened already dangerous conditions at a mine that supplies coltan — a critical material in consumer electronics and defense systems — to global markets.
How the tunnels collapsed
The mine is located about 25 miles (40 kilometers) west of the regional capital, Goma, and employs thousands of miners who work largely by hand. Miners dig long tunnels, often parallel to one another, with limited structural support and no safe evacuation routes in the event of a collapse.
Details about this collapse have been sparse because of the mine’s remoteness and because pressure from rebels and mine owners discourages miners from speaking publicly. Ibrahim Taluseke, a miner at Rubaya, told the Associated Press that mine owners are required to pay $300 to each victim’s family — a financial burden he said creates a direct incentive to suppress the true number of dead.
“Imagine if you give a high number, these owners could even eliminate you. Because often they even hide the victims’ bodies to avoid compensation,” Taluseke said.
Other miners gave varying death tolls from the collapse.
Analysts dispute the cause, not the pattern
Analysts disagree on the precise reasons for the back-to-back collapses, in part because Rubaya is difficult to access.
Christian-Géraud Neema, a nonresident scholar in the Carnegie Africa Program, attributed the collapse to heavy rains and cautioned against drawing a direct causal link to M23’s control of the mines. “It’s normal for Kinshasa to exaggerate the numbers,” Neema said, adding that collapses at Rubaya are common. “We should not be shocked; we should expect another collapse in three weeks’ time or in a month,” he said.
Guillaume de Brier, a researcher with the International Peace Information Service (IPIS), said M23’s takeover is a contributing factor. “Because of M23, there are no more civil society protections or state services,” de Brier said. A lack of regulation during ongoing conflict has increased the number of miners, he added, as many people have lost other sources of work and cannot find employment outside the artisanal mining sector.
What coltan is and why it matters globally
The Rubaya mines produce coltan — short for columbite-tantalite — an ore from which the metals tantalum and niobium are extracted. Both are classified as critical raw materials by the United States, the European Union, China, and Japan.
Tantalum is used in mobile phones, computers, and automotive electronics, as well as in aircraft engines, missile components, and GPS systems. Niobium is used in pipelines, rockets, and jet engines.
M23’s financial stake in the mine
According to a United Nations report, since seizing Rubaya, M23 has imposed taxes on the monthly trade and transport of 120 metric tonnes of coltan, generating at least $800,000 a month. U.N. experts said the coltan is then exported to Rwanda.
Analysts noted that even before M23 seized control of the mine, coltan from Rubaya was sold to Rwanda — the difference being that transactions previously ran through Congolese intermediaries.