Moscow (CNN) Three Russian journalists who were reportedly investigating a paramilitary organization with links to the Kremlin were killed in the Central African Republic this week in what authorities describe as an ambush.

The men were in the country to investigate the activities of Wagner, a shadowy Russian private military firm, a Russian online news outlet, the Center for Investigation Management (TsUR), said in a Facebook post. Anastasia Gorshkova, deputy editor of TsUR, confirmed the journalists were on an investigative assignment in CAR.

Wagner has deployed mercenaries in Syria and Ukraine. The US Treasury has sanctioned the group for recruiting soldiers to fight with separatists in eastern Ukraine, and dozens of Wagner contractors were killed or injured during a firefight with US forces and their allies in Syria in February.

The journalists were identified as Orhan Dzhemal, Alexander Rastorguyev and Kirill Radchenko by documents found with their bodies, the Russian foreign ministry said Tuesday. They were killed near the city of Sibut, about 185 miles north of the capital Bangui. Sibut's mayor, Henri Depele, told Reuters the three were ambushed by armed men who opened fire on their vehicle. Depele said their driver survived.

"The Russian embassy in CAR, unfortunately, was not informed about the presence of Russian journalists in the country," the Russian foreign ministry said in a statement. "Employees of our diplomatic mission are now in close contact with local law enforcement agencies and government agencies to discover all the circumstances relating to the deaths of Russian citizens." Russian law enforcement have opened a criminal probe into their deaths.

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