A landslide earlier this week collapsed several mines at a major coltan mining site in eastern Congo, leaving at least 200 people dead, rebel authorities said Saturday.

The collapse took place Wednesday at the Rubaya mines, which are controlled by the M23 rebels, Lumumba Kambere Muyisa, the spokesperson of the rebel-appointed governor of North-Kivu province told The Associated Press. He said the landslide was caused by heavy rains.

“For now, there are more than 200 dead, some of whom are still in the mud and have not yet been recovered,” Muyisa said. He added that several others were injured and taken to three health facilities in the town of Rubaya, while ambulances were expected to transfer the wounded Saturday to Goma, the nearest city around 50 kilometers (30 miles) away.

The rebel-appointed governor of North Kivu has temporarily halted artisanal mining on the site and ordered the relocation of residents who had built shelters near the mine, Muyisa said.

Congo’s government in a statement on X expressed solidarity with the victims’ families and accused the rebels of illegally and unsafely exploiting the region’s natural resources.

A former miner at the site told The Associated Press there have been repeated landslides because the tunnels are dug by hand, poorly constructed, and left without maintenance.

“People dig everywhere, without control or safety measures. In a single pit, there can be as many as 500 miners, and because the tunnels run parallel, one collapse can affect many pits at once,” Clovis Mafare said.

Rubaya lies in the heart of eastern Congo, a mineral-rich part of the Central African nation which for decades has been ripped apart by violence from government forces and different armed groups, including the Rwanda-backed M23, whose recent resurgence has escalated the conflict, worsening an already acute humanitarian crisis.

Congo is a major supplier of coltan, a black metallic ore that contains the rare metal tantalum, a key component in the production of smartphones, computers and aircraft engines.

The country produced about 40 percent of the world’s coltan in 2023, according to the U.S. Geological Survey, with Australia, Canada and Brazil being other big suppliers. Over 15% of the world’s supply of tantalum from Rubaya’s mines.

In May 2024, M23 seized the town and took control of its mines. According to a U.N. report, since seizing Rubaya, the rebels have imposed taxes on the trade and transport of coltan, generating at least $800,000 a month.

Eastern Congo has been in and out of crisis for decades. Various conflicts have created one of the world’s largest humanitarian crises with more than 7 million people displaced, including more than 300,000 who have fled their homes since December.

Despite the signing of a deal between the Congolese and Rwandan governments brokered by the U.S. and ongoing negotiations between rebels and Congo, fighting continues on several fronts in eastern Congo, continuing to claim numerous civilian and military casualties.

The deal between Congo and Rwanda also opens up access to critical minerals for the U.S. government and American companies.