Election Day in Tucson, Arizona
Sign directs voters to a polling station on Election Day in Tucson, Arizona, U.S. November 3, 2020. Reuters

North Carolina officials have registered 14 instances of potential intimidation or interference with voters and election officials in the run-up to Tuesday's U.S. midterm elections, according to records provided to Reuters on Friday.

The alleged incidents come as grassroots poll observers, many recruited by prominent Republican Party figures and activists, fan out in the lead-up to Tuesday's vote, a trend that has worried experts and officials.

Many of the activists embraced false conspiracy theories, spread by former President Donald Trump, which hold that the 2020 election was marred by fraud and that the upcoming congressional elections are similarly vulnerable.

Incident reports released to Reuters on Friday show that the North Carolina State Board of Elections is tracking eight instances of potential voter intimidation, one of potential voter interference and five of potential interference with election workers during early voting for the midterms. The alleged incidents are spread across nine counties and include major metropolitan areas such as Mecklenburg County, where Charlotte is located, as well as more rural areas.

It is not the only state where officials have raised concerns. Arizona late last month asked the Justice Department to investigate a case of possible voter intimidation, and officials there have since said they have observed several more possible instances of intimidation.

In several other states, aggressive canvassing tactics by Republican-aligned groups have raised voting intimidation concerns among election officials and voting rights lawyers.

Nearly 36 million Americans have so far cast early ballots, either at in-person sites or by mail, according to a tally by the U.S. Election Project.

Most of the North Carolina incidents, which were described in only general terms, involved photographing, videotaping or yelling at voters and officials, the reports show.

In one case in Columbus County in the state's southeast, an observer allegedly followed an election worker in his or her car. In Mecklenburg County, observers allegedly approached election workers as they returned to a government office and photographed their license plates.

"The State Board and its law enforcement partners are monitoring several isolated incidents of possible voter or poll worker harassment or intimidation, as well as cases of aggressive campaigning outside polling places," Karen Brinson Bell, executive director of the North Carolina State Board of Elections, said in a statement.

"We take these incidents very seriously. When they occur, we will work with our law enforcement partners on appropriate responses."

North Carolina officials noted unusually aggressive observers during May's primary election in 16 counties.