A newly discovered Russian-led network of professional trolls was being outsourced to Ghanaian and Nigerian operatives, according to Facebook and Twitter, who removed the network’s accounts on Thursday.

The network was small: just 49 Facebook accounts, 85 Instagram accounts and 71 Twitter accounts in question. But it marks the first time that a Russian information operation targeting the US has been found to be run from Africa.

Nathaniel Gleicher, Facebook’s head of security policy, said the company believes it was such a small network because it was disrupted in the early stages of building its audience. It was, Gleicher said, “operated by local nationals – some wittingly and some unwittingly – in Ghana and Nigeria on behalf of individuals in Russia.

“The people behind this network engaged in a number of deceptive tactics, including the use of fake accounts … to manage pages posing as non-government organisations or personal blogs, and post in groups,” Gleicher added.

“They frequently posted about US news and attempted to grow their audience by focusing on topics like black history, black excellence and fashion, celebrity gossip, news and events related to famous Americans like historical figures and celebrities, and LGBTQ issues. They also shared content about oppression and injustice, including police brutality.”

Although the Facebook network posted a significant amount of content, it steered clear of explicitly political postings. Instead, the desire seems to have been to post content that would grow the audience, while also inflaming contemporary American divides.

“Although the people behind this activity attempted to conceal their purpose and coordination, our investigation found links to EBLA, an NGO in Ghana, and individuals associated with past activity by the Russian Internet Research Agency (IRA),” Gleicher said.

The Twitter accounts shared many similar traits. But an archive of the messages posted by the fake accounts, shared by Twitter, offers extra insight into how Russian information actors are exploiting the coronavirus pandemic for their own ends.

Hundreds of messages in the archive, which covers late January and early February, mention the pandemic, mostly in replies to influential accounts and individuals.

One, bizarrely, warns British reality TV star and 1980s computer magnate Alan Sugar to “be careful” of the coronavirus. Another shares the news that “health officials fear that misinformation about the virus could spark a run on medications”. But most of the tweets simply reflect an urge to jump on popular topics to gain more followers, a reflection of how early the network was discovered.

“These 71 removed accounts, operating out of Ghana and Nigeria and which we can reliably associate with Russia, attempted to sow discord by engaging in conversations about social issues, like race and civil rights,” said Twitter’s safety team in a statement.

During the cold war, the KGB sought to exploit smouldering racial divisions in the US with a series of “active measures”. According to Oleg Kalugin, Moscow’s former spy chief in America, the KGB carried out a series of dirty tricks.

These included writing anonymous racist hate letters to African diplomats in New York, purporting to come from American white supremacists. Kalugin and his fellow KGB officers, posing as journalists, published these letters, quoting them as examples of rampant American racism.

Kalugin said he “lost no sleep” over such tactics, “figuring they were just another weapon in the cold war”. The KGB also planted stories in US publications saying Washington sided with the racist regime in South Africa, he said.

The Soviet Union may be long gone but Moscow’s strategic thinking remains largely unchanged. There is compelling evidence that the Kremlin has sought to reboot KGB methods of propaganda and disinformation via anonymous posts on social media.

According to the US special counsel Robert Mueller, in 2016 trolls working out of the notorious factory in St Petersburg made contact with a number of American black activists.

The Russians posed as a grassroots group, Black Matters US. In February 2017, a Russian troll using the persona Black Fist even hired a self-defence instructor in New York to give classes to black Americans, Mueller reported.

Leaked documents reported on by the Guardian last year showed that Russia was engaged in a renewed push for influence in Africa.