The FBI has launched an investigation after it became known that 3 million voters received automatic phone calls telling them to “Stay safe and stay home” on Election Day, according to a report by the NGO ProPublica.

Some 800,000 of those calls were directed to six swing states.

The data and recordings were provided by the firm TelTech, which owns the RoboKiller smartphone application.

According to the ProPublica report, although the FBI is aware of the situation and is investigating it, it is not yet known who is behind the messages.

Federal investigators also have to determine whether the calls were directed to people registered with a specific political party or whether they fit certain demographics.

One of the messages, only a few seconds long, urged voters to “Stay safe and stay home” in a monotone and robotic tone. 

“Be mindful of people that are trying to intimidate you, undermine your confidence,” a senior Department of Homeland Security (DHS) official told ProPublica.

According to TelTech’s investigation, the calls began in December 2019.

“It did seem potentially like voter disinformation or suppression, given the timing,” said Mariah Montgomery, a Brooklyn nonprofit worker with a Los Angeles area code who received the phone call twice in one day last week.

TelTech data shows that Texas was the state that received the most of these calls—more than 798,000.

It should be noted that while Texas is traditionally a Republican state, the Democratic campaign believed that Joe Biden could eventually achieve a victory there.

Calls to New York and Maryland were also recorded.

A good number of calls pointed to swing states, meaning that they were in play in the election and both candidates were competing for the electoral votes. Florida received 534,000; Pennsylvania, 93,000; Michigan, 89,000 and North Carolina, 60,000.

According to the research, more than 146,000 phone numbers were behind the flood of calls. Some of those who received messages in recent days said the numbers appeared to come from their area code or imitate a similar number pattern to their phone number.

The FBI declined to provide further comment at this time.