Russia has been testing new disinformation tactics in an enormous Facebook campaign in parts of Africa, as part of an evolution of its manipulation techniques ahead of the 2020 American presidential election.

Facebook said on Wednesday that it removed three Russian-backed influence networks on its site that were aimed at African countries including Mozambique, Cameroon, Sudan and Libya. The company said the online networks were linked to Yevgeny Prigozhin, the Russian oligarch who was indicted by the United States and accused of interfering in the 2016 presidential election.

Unlike past influence campaigns from Russia, the networks targeted several countries through Arabic-language posts, according to the Stanford Internet Observatory, which collaborated with Facebook to unravel the effort. Russians also worked with locals in the African countries to set up Facebook accounts that were disguised as authentic to avoid detection.

Some of the posts promoted Russian policies, while others criticized French and American policies in Africa. A Facebook page set up by the Russians in Sudan that masqueraded as a news network, called Sudan Daily, regularly reposted articles from Russia’s state-owned Sputnik news organization.