Washington DC - An Arizona man who allegedly wanted to "incite a race war" ahead of the November US presidential election has been indicted on firearms charges, the Justice Department said Wednesday.

Mark Adams Prieto (58) of Prescott was indicted by a federal grand jury on Tuesday and faces up to 25 years in prison, the department said in a statement.

Prieto entered into discussions between January and May with two individuals to "devise a plan to commit a mass shooting of African Americans and other minorities to incite a race war prior to the 2024 US Presidential Election," it said.

Prieto believed the two individuals "shared his racist beliefs," but they were, in fact, "working with the FBI," the department said.

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Prieto allegedly sold two rifles to the individuals and was taken into custody while driving through New Mexico on May 14.

He had an additional seven firearms on him at the time, and more guns were found at his residence, the Justice Department said.

The target for the planned mass shooting was a concert that was to be held in Atlanta, Georgia, on May 14 and 15.

Prieto is charged with firearms trafficking, transfer of a firearm for use in a hate crime, and possession of an unregistered firearm.