The men from Gaston County, near Charlotte, were arrested by federal authorities on Saturday after more than a month's investigation.

Walter Eugene Litteral, 50, Christopher James Barker, 41, and Christopher Todd Campbell, 30, are accused of stockpiling guns and ammunition, as well as attempting to manufacture pipe bombs and live grenades from military surplus "dummy" grenades, according unsealed criminal complaints released Monday.

The close to 60 pages of information compiled by federal authorities since July include allegations Litteral planned to makes explosives out of tennis balls covered in nails and coffee cans filled with ball bearings.