Facebook on Monday yanked four foreign-based networks, including one linked to Russia’s Internet Research Agency, which has been indicted for alleged interference in the 2016 U.S. presidential election.

The Russian accounts pulled on Monday targeted the 2020 candidacy of former Vice President Joe Biden.

The 50 Instagram and single Facebook account linked to the Internet Research Agency had at least 246,000 followers. Instagram is owned by Facebook.

“This campaign showed some links to the Internet Research Agency (IRA) and had the hallmarks of a well-resourced operation that took consistent operational security steps to conceal their identity and location," said Nathaniel Gleicher, head of Cybersecurity Policy for Facebook, in a statement. “The people behind this operation often posted on both sides of political issues including topics like US elections, environmental issues, racial tensions, LGBTQ issues, political candidates, confederate ideas, conservatism and liberalism. They also maintained accounts presenting themselves as local in some swing states, and posed as either conservatives or progressives.”

He added, “All of these operations created networks of accounts to mislead others about who they were and what they were doing. We have shared information about our findings with law enforcement, policymakers and industry partners.”

Although the accounts posed as Americans from all sides of the political spectrum, many were united in their opposition to Biden, according to Graphika, a social media investigations company that Facebook asked to analyze the accounts.

“It looked like there was a systematic focus on attacking Biden from both sides,” Graphika director of investigations Ben Nimmo, who analyzed the accounts, told CNN Business.

Russian trolls used social media to interfere in the 2016 election, going after Hillary Clinton from the right and also trying to spread a perception on the left that she was not progressive enough.

In February 2018, the U.S. Department of Justice indicted 13 Russian nationals and three Russian entities, including the Internet Research Agency, in special counsel Robert Mueller’s investigation into interference in the 2016 U.S. presidential election.

The three other networks shut down by Facebook originated in Iran and targeted a number of different regions of the world including North Africa and Latin America.