KINSHASA, March 28 (Xinhua) -- At least nine people were killed and 12 others injured in a mine collapse in the Rubaya mining area of the eastern Democratic Republic of the Congo (DRC), local media reported on Saturday, following a series of recent deadly accidents in the region.

The accident occurred on Friday at the Gasasa mining site in Rubaya, where two shafts suddenly collapsed as artisanal miners were descending into underground galleries to extract minerals, according to the local media. Some of the injured are in critical condition, local sources were quoted as saying.

Rescue operations have been hampered by unstable ground conditions and a lack of appropriate equipment, a common challenge at artisanal mining sites where safety standards are often minimal.

The Rubaya mining zone has been under the control of the March 23 Movement rebel group since 2024. The area was reclassified by the DRC government since November as a "red zone," formally prohibiting mining and mineral trading.

Rubaya has witnessed repeated mining disasters. Earlier this month, a mine collapse triggered by heavy rains claimed more than 200 lives, including around 70 children. In January, several shafts collapsed at coltan mining sites, reportedly killing at least 200, with some estimates exceeding 400, excluding those still missing.

Local media reports noted that the latest incident is not isolated. Several similar accidents have been reported in recent weeks in and around Rubaya, though exact casualty figures remain difficult to verify due to limited access to some areas.

Coltan, or columbite-tantalite, is the main source of tantalum, a rare metal used in the production of advanced electronic devices. The United Nations estimated that the Rubaya mines alone account for about 15 percent of the global tantalum supply. ■