(CNN) — Attorney General Merrick Garland on Monday vowed that the US Justice Department “will not permit voters to be intimidated” during November’s midterm elections.

“The Justice Department has an obligation to guarantee a free and fair vote by everyone who’s qualified to vote and will not permit voters to be intimidated,” Garland said during a press briefing.

More than 7 million ballots have already been cast across 39 states as of Monday, according to data from election officials, Edison Research and Catalist. But with two weeks until November 8, law enforcement agencies and officials are turning their attention toward Election Day and the potential for violence amid threats to election workers and reports of voter intimidation.

In Arizona, the Secretary of State’s Office has already referred six reports of potential voter intimidation near ballot drop boxes to law enforcement, along with a report of election worker harassment.

In one instance, which has been referred to the Department of Justice and Arizona Attorney General’s Office, an unidentified voter reported that they were approached and followed by a group of individuals when trying to drop off their ballot at an early voting drop box. The group made accusations against the voter and their wife, as well as took photographs of them and their license plate and followed them out of the parking lot, according to the report.

In another instance, two armed individuals — dressed in tactical gear — were spotted at a ballot drop box in Mesa, Arizona, on Friday night, according to Maricopa County officials. The pair left the scene when the County Sheriff’s Office arrived.

“We are deeply concerned about the safety of individuals who are exercising their constitutional right to vote and who are lawfully taking their early ballot to a drop box,” Maricopa County Board of Supervisors Chairman Bill Gates and Recorder Stephen Richer said in a joint statement on Saturday.

Maricopa County Sheriff Paul Penzone on Monday said the two armed individuals were not breaking the law, but condemned people trying to “passively intimidate others trying to just cast a vote.”

Dozens of Republicans trying to be elected in 2022 as governor, state secretary of state or US senator have joined former President Donald Trump in baselessly rejecting or questioning the legitimacy of President Joe Biden’s victory in 2020, with some having attempted to overturn the 2020 results. Such unfounded allegations of widespread election fraud inspired a slew of restrictive new voting laws and has led to growing safety concerns around elections.

Last year, the Justice Department launched a task force to address the rise in threats against election officials, and safety preparations are already well underway for Election Day across the country.

In Colorado, for example, a state law — the Vote Without Fear Act — prohibits carrying firearms at polling places or within 100 feet of a ballot drop box. And in Tallahassee, Florida, officials have added Kevlar and bullet-resistant acrylic shields to the Leon County elections office, said Mark Earley, who runs elections in the county.

‘Incredibly heightened threat environment’

Samantha Vinograd, Department of Homeland Security assistant secretary for counterterrorism, threat prevention, and law enforcement, on Monday said the agency is “certainly very focused on what we consider to be an incredibly heightened threat environment” ahead of November’s elections. She cited conspiracy theories swirling online and the history of extremist groups in the United States as reason for concern.

“We know that there’s a historical basis for violence associated with elections,” said Vinograd, a former CNN contributor, while speaking at the 2022 Homeland Security Enterprise Forum. “At the same time, anybody with a Twitter account or a Facebook account, or who watches the news is aware that myriad conspiracy theories continue to proliferate with various narratives associated with false claims about the election.”

Amid the threat, she said that DHS — and its Cybersecurity and Infrastructure Security Agency, in particular — is working to protect election security infrastructure.

The FBI and sheriffs representing some of America’s biggest counties, meanwhile, have discussed the possibility of misinformation fueling violence at polling stations during the midterm elections, a representative of a sheriff’s association told CNN.

The briefing last week covered how law enforcement can balance supporting the security needs of election officials without risking intimidating voters by being “out in force” near polling stations, said Megan Noland, executive director of Major County Sheriffs of America, which represents the 113 largest sheriff’s offices in the country. The recent surveillance by private citizens of ballot drop boxes was also discussed, Noland said.

Neal Kelley, a former election official who also presented at the briefing, told CNN that the potential for confrontations at ballot drop boxes “is something that we need to watch.” The FBI declined to comment on the briefing.

The FBI, Kelley said, gave an overview of the threat environment facing election officials.

“The whole idea was to give [sheriffs] an idea on how they can collaborate with their election officials because there’s not a lot of that happening nationwide,” Kelley, the former chief election official of Orange County, California, said of his presentation. Big counties have some of that collaboration between cops and election officials, but smaller ones often don’t, he said.

One idea discussed at the briefing was giving patrol officers a list of election criminal codes that they could keep in their pockets when responding to any incidents on Election Day, Kelley told CNN.

“If you’re calling 9-1-1 on Election Day as an election official, it’s too late,” he said.