False rumors about antifa organizing bus rides to take protesters into white neighborhoods and loot residences have gone viral in recent days on digital neighborhood platforms and in group texts throughout the U.S.

Some of the posts feature a screenshot of a tweet by a fake antifa Twitter account that Twitter said was created by the white nationalist group Identity Evropa, attempting to drum up fear of looting in residential and suburban areas. The false antifa tweet was boosted in part by Donald Trump Jr., who posted a screenshot of the tweet to his Instagram account. Other rumors falsely warn of antifa members being “bused in” to towns in Idaho.

The social media rumors about outsiders coming to damage property or commit acts of violence at protests have ripped through local communities over the last week, aided by neighborhood-focused social media networks and groups.

Rumors circulating on Facebook and Nextdoor that buses filled with thousands of antifa and other outside agitators on their way to loot “white neighborhoods” prompted law enforcement to respond to fearful residents in the Sacramento suburbs that they are “monitoring” messages on social media “causing worry and concern.”

In Idaho, online militia groups warned local businesses that antifa activists were coming on buses to vandalize the city of Boise and residential areas. On Monday, the Sheriff’s Office of Payette County, north of Boise, posted on its Facebook page to debunk the rumor. Another viral rumor warned Idahoans to “lock our doors and our guns” because antifa activists were being flown in from Seattle.

“The Payette County Sheriff’s Office has not had contact with and has not verified that Antifa is in Payette County,” its post read.

In South Dakota, Sioux Falls Police Chief Matt Burns had to refute claims that buses were coming from Fargo to incite violence.

“In any event like this with this much exposure, there is lots of information floating around out there on social media,” Burns told The Argus Leader, a local newspaper. “Some of it has some truth to it, and some of it is just a false flag. It appears at this time that that’s what that was.”

Similar claims are sweeping social media in rural areas throughout the country, according to Matt Hildreth, the executive director RuralOrganizing.org, a national progressive nonprofit.

Hildreth said his national network of rural community leaders “are being overwhelmed” by claims from social media about out-of-towners riding in on buses to infiltrate local protests.

“Misinformation campaigns are specifically targeting these communities,” Hildreth said. “It seems to be specifically attempting to stoke fear and paranoia, especially in response to what we’re seeing in Minneapolis.”

The impostor antifa tweet gained considerable traction on hyperlocal apps like Nextdoor and the Ring app in communities across the country, as seen in screenshots shared with NBC News. The tweets share a screenshot, sometimes with captions like “Antifa in the suburbs?” sparking fearful comments among rural and suburban communities.

Screenshots of the fake antifa tweet are still swirling around group texts nationwide, according to several people who group forwarded the claims to NBC News. The spread of false, context-free screenshots are known as “hidden viral” texts by disinformation researchers, in part because the spread of viral misinformation and rumors is exponential but almost impossible to responsibly track due to the private nature of text messages.

“As the specter of danger looms, people will take screenshots and circulate misinformation on other messaging apps,” said Joan Donovan, the director of Harvard Kennedy School’s Shorenstein Center on Media Politics and Public Policy. “This is where it becomes impossible to trace it’s impact and potentially could lead to roving vigilante groups. It’s crucial to identify these hoaxes early and quickly.”

The screenshots are usually attached to an appeal toward familiarity or authority, with phrases like “my friend sent me this” and “please pass this along,” an effort to gain maximum exposure and prey on fear.

The fake antifa account that went viral left clues that its tweets weren’t genuine. The account spelled misspelled the legitimate hashtag “#blacklivesmaters.” And inside the antifa flag in @Antifa_US’s profile picture, the account appended an “IE,” short for Identity Evropa, which rebranded as “American Identity Movement” in 2019.

But some other disinformation accounts aren’t so willing to claim credit.

On Tuesday, Facebook added a warning to posts on Facebook and Instagram indicating the fake antifa post was “false information.”

By then the post had already gone viral on both platforms, generating hundreds of thousands of interactions.

The post was shared by pro-Second Amendment and conservative media pages like Red State and Hot Air. It was also shared by “U.S. Law Enforcement,” a page with nearly half a million followers that claims to be “run by several current and retired U.S. law enforcement officers,” which posted the screenshot of the tweet and wrote, “Antifa is warning that tonight they’re moving out of the cities — and into residential areas to ‘take what’s ours.’ Law enforcement across the country on high alert. Circulate this asap.”

The posts then moved quickly through pro-Trump Facebook groups.

Ray Serrato, an independent disinformation researcher, first tracked the viral spread through Crowd Tangle, the Facebook-owned social media analysis tool. NBC News replicated his results.

The post was also widely shared on Instagram, led by Trump Jr., who shared the post on Sunday and wrote, “Absolutely insane. Just remember what ANTIFA really is. A Terrorist Organization! They’re not even pretending anymore.” His post was liked 96,000 times. Trump Jr. did not respond to a request for comment, but deleted the post on Tuesday morning.