Virginia election officials said Monday that six mailboxes in the central portion of the state were broken into over the weekend, potentially resulting in the loss of an unknown number of absentee ballots.

The break-ins, a federal crime, occurred in mailboxes located in the City of Richmond and Henrico and Chesterfield counties, state election officials said in a news release.

“At this time, the United States Postal Service is investigating,” the news release said. “Neither the Department nor USPS has any information about whether any election mail was contained in the boxes.”

A Postal Service inspector for Virginia did not immediately respond Monday to a request for more details.

The incidents tapped into worries about the security of mail-in voting at a time when more voters who are worried about being infected by the coronavirus are choosing that option instead of voting in person.

President Trump has heightened those worries by repeatedly alleging without evidence that the mail-in voting process is filled with fraud.

The affected outdoor mailboxes were at the following locations:

In Henrico County, 4990 Sadler Place, 2000 Starling Drive and 2100 E. Parham Road. In Chesterfield County, 7510 Lady Blair Lane and 1201 Sycamore Square Drive. In Richmond, 805 Glenburnie Road.

State election officials encouraged voters who dropped off their absentee ballots at those sites between Saturday at 3 p.m. and Monday at 7 a.m. to go to the “check my registration status” section on this page to confirm that they were received. Those affected voters should also call the Postal Service at 877-876-2455 to report the incident, election officials said.

Voters in need of a should ballot can contact their local voter registrar.