Facebook said Wednesday it took down accounts linked to a Russian ally of President Vladimir Putin seeking to spread disinformation on the social network in eight African countries.
The operations hiding behind fake identities were linked to Yevgeny Prigozhin, who has been indicted in the United States in connection with an influence campaign targeting the 2016 US elections.
"Each of these operations created networks of accounts to mislead others about who they were and what they were doing," Facebook cybersecurity chief Nathaniel Gleicher said in a statement.
"We have shared information about our findings with law enforcement, policymakers and industry partners."
The accounts originated in Russia and targeted Madagascar, Central African Republic, Mozambique, the Democratic Republic of Congo, Ivory Coast, Cameroon, Sudan and Libya, according to Facebook.
The move is the latest effort by the social media giant to halt foreign influence efforts in the United States and other parts of the world.
The company described three separate operations targeting both Facebook and Instagram users.
One operation included 35 accounts and 53 pages that focused on Central African Republic, Mozambique, Democratic Republic of Congo, Ivory Coast and Cameroon.
The effort attracted some 475,000 followers and spent $77,000 for ads posting on global and local political news including Russian policies in Africa and criticism of French and US policies.
A separate operation targeting Sudan included 20 different accounts and 18 pages, some posing as news organizations.
The third network, focused on Libya, involved 15 accounts and 12 pages posting about local news and geopolitical issues.
"We're constantly working to detect and stop this type of activity because we don't want our services to be used to manipulate people," Gleicher said.
"In each of these cases, the people behind this activity coordinated with one another and used fake accounts to misrepresent themselves, and that was the basis for our action."
Link to mercenary group
Stanford University researchers who worked in parallel with Facebook on the investigation said at least some of the Facebook accounts came from Russia's Wagner Group, a shadowy private army which is believed to have been active in conflicts in Syria and Ukraine, and sent mercenaries to the Central African Republic and Sudan.
Prigozhin is believed to be behind the Internet Research Agency, which has been linked to US election interference, as well as the Wagner Group.
A statement from Stanford's Cyber Policy Center said the operations appear to be "at least in part at the behest of a state actor" but also relied on subcontractors who are native speakers or people within the region, making it harder to detect.
"In addition to well-known social media platforms such as Twitter and Facebook, the actors leveraged public WhatsApp and Telegram groups," the Stanford team said.
"The operation used social media engagement tactics designed to develop a close relationship with the audience, including Facebook Live videos, Google Forms for feedback, and a contest."
The researchers said the operation appears to be part of "Russia's global strategy for reasserting itself as a geopolitical superpower" and follows the deployment of paramilitary groups in Libya and the Central African Republic.
Putin last year surprised the West with a string of high-profile moves that strengthened Russia's influence in the CAR, an extremely poor but strategically important country that has traditionally had close ties to France, the former colonial power.
Russia sent military trainers to the CAR's beleaguered armed forces, a senior aide to advise the president and mercenaries to provide his security, and offered to mediate between the government and the country's many rebel groups.