Three nations have agreed with the help of Russian troops to secure a gold-rich region in the Central African Republic rife with armed rebel groups, the latest sign of Moscow’s expanding influence on the continent.

A deal struck last month between the CAR, Chad and Sudan aims to fight armed groups operating along the mineral-rich borders with the two neighboring states, Hassan Bouba, a powerful ex-rebel leader who now serves as CAR’s livestock minister, said in a phone interview. During a trip to Chad on Sunday, Sudanese General Abdel Fattah Al-Burhan said both countries agreed to “achieve security and stability” in CAR.

The agreement further embeds Russia in the politics and security of the region at a time when the West is trying desperately to curtail Moscow’s growing footprint. The Kremlin has in recent years strengthened ties to African nations including Libya, Sudan, Mali and Burkina Faso.

Western governments including the European Union and the US, United Nations officials, humanitarians and rebel fighters say that the Wagner Group — a private mercenary firm with close ties to the Kremlin that was hired by CAR’s government in 2018 to fight a decade-long rebel insurgency — has concentrated on securing diamond and gold mines across the country. CAR’s government maintains that the only Russian forces in the country are unarmed trainers.

Most of the CAR has been outside of state control for the past decade, subject instead to the power of various rebel factions fighting for access to the country’s vast gold and diamond reserves.

Russian Ministry of Defense spokesman Igor Konashenkov didn’t respond to a request for comment sent by text message. A Chadian presidency official declined to comment.

Last year, government forces – backed by Russian troops – attempted to take control of resource-rich areas in northeastern CAR, according to Enrica Picco, Central Africa project director for the International Crisis Group and a former member of the UN panel of experts on CAR.

“This really sparked tensions between the armed groups that were trying to protect their last source of revenue in the north of the country and the government forces and Russian allies,” Picco said. The deal struck this month will destabilize the region even further, she said.

Abdu Buda, a spokesman for the rebel UPC, said fighting has begun intensifying in northeastern CAR.

“There are many resources in this area and our enemies have come to leave their businesses and machinery in our territory,” he said.