United States intelligence officials have been quietly issuing warnings to government agencies all summer about a rising threat of extremist violence tied to the 2024 presidential election, including plots to destroy bins full of paper ballots and promote “lone wolf” attacks against election facilities throughout the country.

In a series of reports between July and September, analysts at the Department of Homeland Security warned of a “heightened risk” of extremists carrying out attacks in response to the race. Copies of the reports, first reported by WIRED, describe efforts by violent groups to provoke attacks against election infrastructure and spread calls for the assassinations of lawmakers and law enforcement agents.

Last month, the agency’s intelligence office emphasized in a report that “perceptions of voter fraud” had risen to become a primary “trigger” for the “mobilization to violence.” This is particularly true, the report says, among groups working to leverage the “concept of a potential civil war.” Fears about “crimes by migrants or minorities” are among other top “triggers,” it says.

The documents show that DHS alerted dozens of agencies this summer to online chatter indicating potential attacks on election drop boxes—secured receptacles used in more than 30 states to collect mail-in voter ballots. The text highlights the efforts of an unnamed group to crowdsource information about “incendiary and explosive materials” capable of destroying the boxes and ballots. An extensive list of household mixtures and solvents, which are said to render voter ballots “impossible to process,” was also compiled by members of the group, the report says, and were openly shared online.

DHS did not respond to multiple requests for comment. The FBI, which is on a distribution list for several of the reports, declined to comment.

The reports were first obtained by Property of the People, a nonprofit focused on transparency and national security, under open records law. The reports contain details about how to commit crimes and avoid law enforcement, which WIRED is not publishing.

Wendy Via, cofounder and president of the Global Project Against Hate and Extremism (GPAHE), says the conclusion reached by DHS matches the consensus of experts in the field: “Election denialism is going to be the primary motivator—if there is going to be violence.”

For decades, a growing number of states have adopted election drop boxes as a way to offer voters a dedicated, secure, and convenient way to submit voter ballots ahead of elections. Today, as many as 35 states allow drop boxes in some capacity, though a handful—nearly all southern—have outlawed their use, mostly over baseless claims about fraud and ballot stuffing. While drop boxes are no less secure than other forms of voting, Republicans have scrambled to block their use in key states, including Wisconsin, where Donald Trump blasted legislation expanding drop boxes as “only good for Democrats and cheating.” Via points to the Republican-led campaign aimed at banning and restricting access to election drop boxes in Wisconsin as a flash point for election denialism and possible violence.

The obsession with the otherwise mundane practice of dropping off ballots prior to election day stems in large part from the widely discredited film 2,000 Mules. The “documentary” depicts a shadowy network of operatives attempting to sway the 2020 election by stuffing ballots in Joe Biden’s favor; the film’s publisher, a conservative media company, has since issued an apology.

While the film’s evidence turned out to be false, it nevertheless provoked a surge of intimidation from far-right groups targeting drop-box voters and the officials defending their use. For the November election, some groups have committed to fundraising in order to surveil the boxes around the clock over public livestream. Others have hosted events near the locations to push conspiracy theories about immigrants. Election denial groups such as True the Vote, meanwhile, are working with myriad others across the country, as WIRED reported this summer, and are establishing a web of operations for waging legal warfare in the aftermath of the vote—if Trump fails to retake the White House a second time.

Spurious claims of voter fraud have remained a mainstay of the former president’s reelection efforts, with Trump preemptively and baselessly claiming that should he lose in November, the election will have been rigged. Claims that the 2020 presidential election was stolen have been exhaustively investigated and debunked by countless judges and state election officials across the country. Property of the People executive director Ryan Shapiro says that though DHS does not mention the political leanings of the subjects in its reports, he believes “the documents make plain that US intelligence is bracing for election- and immigration-related violence from Trump’s MAGA minions.”

The concerns of DHS today are reminiscent of warnings shared by the agency two years ago during the midterm elections. Similar bulletins leaked then showing fears among federal security officials that extremists would mount an attack, threaten poll workers, or sabotage infrastructure. The concerns proved largely unwarranted, outside of scattered instances of armed men in paramilitary gear showing up to “monitor” ballot boxes across Arizona—an effort quietly spearheaded in part by True the Vote, which helped make 2,000 mules, involving militias that included the American Patriots Three Percent, an anti-government group.

The election threats flagged in the reports by DHS appear to be growing more extreme over time. No longer restricted to aggressive surveillance and loitering outside polling locations, the risks associated by DHS with election fraud conspiracies today more closely resemble traditional acts of terrorism.

There are, however, some deterrents. The arrests and prosecutions of rioters involved in the January 6 attack on the United States Capitol building are credited by DHS, as well as groups such as GPAHE, with stifling much of the enthusiasm that far-rights groups once held for turning out in big numbers.

“In my lifetime of working in civil rights, the January 6 arrests are the only time I’ve ever seen an arrest or prosecution work as a deterrent,” says Via. “They really do not want to go to jail.”