Election officials in Florida and Alaska have begun investigating intimidating pro-Trump emails sent to Democratic voters that appear to have been made to look as if they were sent by the far-right Proud Boys. “You will vote for Trump on Election Day or we will come after you,” read the emails, which also told voters to change their party affiliation to Republican. The messages warned voters against disobeying the instructions, noting that “we are in possession of all your information” from voter registration lists. The emails were sent using the domain officialproudboys.com, which had been used by the Proud Boys until recently, when its registration was canceled by the hosting company and the domain was apparently left wide open, according to The Washington Post. The Proud Boys denied involvement, and experts have said the emails do appear to be spoofed.

Citing the cybersecurity firm Crowdstrike, CBS News reported that the messages were traced back to a cloud infrastructure provider based in Saudi Arabia. John Scott-Railton, a senior researcher at the Citizen Lab at the University of Toronto’s Munk School of Global Affairs and Public Policy, wrote on Twitter that whoever was behind the messages had used “some simple trickery to appear to come from” the Proud Boys domain. “This is what election interference looks like,” he was quoted telling The Washington Post.