The FBI is investigating dubious robocalls that told voters in several states to 'stay safe and stay home' on Election Day

The FBI is investigating reports of suspicious robocalls and texts urging voters to "stay safe and stay home" on Election Day, a senior cybersecurity official told reporters on Tuesday.

"Robocalls of this nature happen every election," the official from the Cybersecurity and Infrastructure Security Agency said during a media call, adding that the calls were a "voter intimidation" and "voter suppression" tactic.

Officials in Michigan said that some voters in Flint — part of a county that leans Democratic — also received calls telling them to go to the polls on Wednesday to avoid long lines on Tuesday.

Michigan Gov. Gretchen Whitmer said on Tuesday that state officials would "work quickly to stamp out misinformation," and the FBI's focus on the matter signals that federal officials are also taking it seriously.

Dana Nessel, Michigan's Attorney General, said she'd also received reports of calls telling voters that they should wait and vote on Wednesday because polling locations were backed up with long lines on Tuesday.

"Obviously this is FALSE and an effort to suppress the vote. No long lines and today is the last day to vote. Don't believe the lies," she tweeted.

Similar robocalls were reported in Kansas and Nebraska. In both states, officials urged voters to ignore the false claims and head to the polls. 

People who received the calls said they heard a computerized female voice saying: "Hello, this is just a test call. Time to stay home. Stay safe and stay home." Some said they believe the calls were intended to scare them away from the polls.

The Washington Post reported that about 10 million such robocalls had gone out to voters across the US in recent days and started in the summer.

Alex Quilici, CEO of YouMail, a company that has been monitoring the robocalls, echoed the Post estimate. "We don't know uniqueness exactly, but our best, educated estimate would be that they've hit 10 million plus people over time," he told Business Insider.

Asked about the possible motivation behind the calls, Quilici said, "We're wondering if it's heading toward an attempt to cause some election or post-election chaos."

USTelecom, a US-based trade association, is also actively tracing these calls, according to spokesperson Brian Weiss.

The calls are "possibly coming from Europe even after going through providers based elsewhere in the world," Weiss told Business Insider. "The call originator is using 'neighborhood spoofing.' That is a technique to mimic the area code and first three digits of the number to appear familiar to recipients."

YouMail says that the calls have reached 280 of the country's 317 area codes since they began in the summer, The Post reported.

As Business Insider has reported, even during the coronavirus pandemic, in-person voting is still a safe option, and there are several tips for voters to safely and securely cast ballots on Election Day.

Overall, US officials have taken more steps this year than in previous election cycles to make the public aware of malicious efforts to suppress the vote, manipulate the electoral process, and sow chaos ahead of Election Day.

The US intelligence community determined over the summer that Russia and China were interfering in the 2020 election: China wanted Joe Biden, the Democratic nominee, to win, while Russia wanted President Donald Trump to stay in power.

Director of National Intelligence John Ratcliffe also announced late last month that Russia and Iran were attempting to "influence public opinion" ahead of the election.

Ratcliffe said Iran was meddling to "damage President Trump" — but Politico reported that the reference to Trump was not in Ratcliffe's prepared remarks and blindsided FBI Director Christopher Wray and Chris Krebs, a senior official in the Department of Homeland Security, both of whom flanked Ratcliffe during the announcement.

Ratcliffe also said Russian and Iranian actors had obtained some voter-registration data, though as ProPublica's Jessica Huseman noted, most of that information is public anyway, and Ratcliffe did not indicate whether any election systems had been breached. He added that officials "have not seen the same actions from Russia" but "are aware that they have obtained some voter information just as they did in 2016."

The New York Times reported that officials thought Russia planned to meddle in the election to help Trump in part by "exacerbating disputes around the results." Ratcliffe did not share that information during his announcement, and The Times said some officials believed that, contrary to what Ratcliffe said, Russia posed a far greater threat to the election than Iran.

US officials' latest discovery about Russia's actions had several parallels to the Kremlin's elaborate and wide-ranging campaign to interfere in the 2016 campaign to boost Trump and denigrate his Democratic opponent, Hillary Clinton.

This time, Russian actors breached state and local networks that could allow them "broader access to American voting infrastructure," The Times said. However, just like in 2016, there is no evidence that the hackers changed vote totals or manipulated registration information.