WASHINGTON >> Two suspected Iranian computer hackers have been charged in a broad campaign of election interference aimed at intimidating American voters during last year’s presidential race and undermining confidence that the results of the contest could be trusted.

The activities, prosecutors say, exploited not only computer vulnerabilities but also existing social divisions to sow discord and confusion among voters. The Iranian cyber campaign included bogus emails that targeted Democratic and Republican voters with different messages, the distribution of a fabricated video that purported to show acts of election fraud and an unsuccessful effort the day after the election to gain access to an American media company’s network.

The overall effort attracted publicity in the run-up to the November 2020 election, when law enforcement and intelligence officials held an unusual evening news conference to accuse Iran of orchestrating an email campaign aimed at intimidating Democratic voters in battleground states so they would vote for Trump.

The indictment makes clear that even as much of the public concern about foreign interference in last year’s election centered on Russian efforts to disparage Trump’s challenger, Joe Biden, Iranian hackers were engaged in a wide-ranging influence campaign of their own.

U.S. intelligence officials said in a March assessment that Iran’s efforts were aimed at harming Trump’s reelection bid but that there was no evidence that Tehran or any other foreign actor had done anything to change the vote totals.

The indictment, filed in the federal court in Manhattan and unsealed on Thursday, accuses Iranian nationals named Seyyed Mohammad Hosein Musa Kazemi and Sajjad Kashian of helping orchestrate the scheme. The Treasury Department also announced sanctions against the men, their colleagues and the company they worked for.

The defendants are not in custody and are believed still to be in Iran, but officials hope the indictment and accompanying sanctions will restrict their ability to travel.

Court documents allege vast efforts, even after the election, to spread disinformation about the presidential contest and to intimidate and pressure voters. While the defendants did not attempt to change the vote totals, officials say, they created the appearance that the election results could not be trusted by leaving the false impression that it was possible to submit fraudulent ballots.

As part of the cyber campaign, officials say, the hackers attempted to compromise voter websites in 11 states and successfully downloaded voter information of more than 100,000 people in one state.

They also sent Americans what officials describe as carefully curated messages, specifically tailored to appeal to members of both major political parties.

That included messages that purported to be from a far-right group, the Proud Boys, that threatened Democratic voters with physical harm if they didn’t change their party affiliation and vote for Trump. To Republican officials and people associated with the Trump campaign, the indictment says, the hackers crafted Facebook messages that falsely claimed that Democrats were planning to commit voter fraud.

A manufactured video spread through social media platforms purported to show an individual hacking into state voting websites and registering fraudulent absentee ballots.

In September and October 2020, according to the indictment, the hackers gained unauthorized access to the computer network of an American media company — prosecutors would not say which one — that provided a content management system for dozens of publications. They tested the capability to modify and create content on the system, which the indictment says “would have provided them another vehicle for further disseminating false claims concerning the election.”

On Nov. 4, 2020, the day after the election, hackers attempted to access the system through stolen credentials, but by that point, the company had fixed the issue and the hackers’ log-in attempt failed, the indictment says.