The news comes amid mounting reports of disinformation being spread online amid the protests over the killing of George Floyd.
The account, with the handle @ANTIFA_US, was traced back to be a false facade for the white nationalist group Identity Evropa. It was specifically called out by U.S. law enforcement as an example of a left-wing radical group attempting to incite violence amid the unrest and nationwide protests.
"This account violated our platform manipulation and spam policy, specifically the creation of fake accounts. We took action after the account sent a Tweet inciting violence and broke the Twitter Rules," a Twitter spokesperson told ABC News.
Twitter has taken action on other fake accounts linked to Identity Evropa. The accounts were engaged in hateful conduct focused on issues of race, religion and sexual orientation.
Before the fake antifa account was suspended, it drew significant media attention for a tweet that incited violence, according to Twitter.
Antifa -- short for "anti-fascists" -- is not a single organization but rather an umbrella term for far-left-leaning militant groups, according to the Associated Press.
A spokesperson for Facebook told ABC News Wednesday it removed a "handful of largely dormant" pages and accounts connected to the account posing on Twitter as Antifa. The social network said it also worked to block the sharing on its platform of screenshots of the original Twitter post.
In a separate move, Facebook also said it had "identified and removed networks of accounts" linked to two other far-right right groups, one of which, identified as American Guard, Facebook said was discussing attending local protests armed with weapons, as first reported by CNN. Facebook said it had already been working to remove the accounts because the groups had been previously banned, but the social media giant "accelerate[d] our investigation and enforcement" because the talk related to the ongoing protests.
Meanwhile, as the protests over Floyd's death continue to roil the nation, social media has become ripe with disinformation.
"Time and time again we have seen public figures, media personalities and even government officials amplifying disinformation and extremist rhetoric intended to inspire violence," John Cohen, a former senior Department of Homeland Security official and current ABC News contributor, said. "A great step in deescalating the violence currently facing the Nation would be for this to end.”
Twitter said it is also actively investigating the hashtag #dcblackout and have suspended hundreds of "spammy accounts" that were using it on Monday.
The hashtag first started trending on Monday morning. Twitter users posted about an internet blackout in Washington, D.C., and a cover-up attempt to silence protesters via the hashtag.
Internet monitor NetBlocks said, however, there was no indication of mass-scale internet disruption in the nation's capital in the last 48 hours. As disinformation spread about the internet blackout, a counter-narrative was also apparently being boosted by bots alerting people that the #dcblackout was "misinformation."
It appears the goal of these efforts was to sow confusion and fear.
"Our teams have been taking action proactively on any coordinated attempts to disrupt the public conversation around this issue," a Twitter spokesperson said.
Meanwhile, the National Capital Region Threat Intelligence Consortium issued an alert Monday, saying that in the last 24 hours unknown entities have been spreading disinformation in order to fuel violence amid the ongoing protests and unrest. "Late Sunday night, May 31, 2020, social media reports began to surface claiming that protesters 'broke into' the White House, gun shots around the area were heard, and that President Trump and his family fled to Kansas," the alert stated.
The alerted added that the Twitter post featured a video with a large group of people running up steps toward a building with white columns.
"However, this video did not feature the White House, but appeared to be filmed in front of the steps of the State House in Columbus, Ohio," it added. "Multiple Twitter accounts, some of which appeared to behave in a bot-like manner and featured Arabic writing on their profiles, began to retweet this video, perpetuating the spread of disinformation. Some Twitter users recognized the building featured in the video and attempted to correct the narrative."
The analysts also wrote about the #dcblackout hashtag, saying a number of "legitimate and bot-controlled accounts retweeted this message."
The actors behind the social media campaign remain unknown, "but the intent of the messaging appears to be an attempt to instill fear and cause confusion among the populace," according to the alert.
A report issued by the Federal Bureau of Investigation's Washington field office analyzing the impact of the demonstrations in the D.C. area found online messages calling for attacks on places including the American Israel Public Affairs Committee headquarters in D.C. and Federal Reserve banks across the country.
Fake videos have also been distributed online that purportedly showed D.C. cops shooting black people and bogus messages willing to pay people to be "professional anarchists," according to the FBI report.
Even though President Donald Trump and other senior officials insist that law enforcement's concerns are confined to agitators on the political left, the FBI report states that "some militia members issued calls to travel to participate in the demonstrations, as part of their anti-law enforcement and anti-government agenda."
This report was updated Wednesday, June 3, to include actions taken by Facebook. ABC News' James Meek, Daniel Linden, Lucien Bruggeman and Lee Ferran contributed to this report.