Two Minnesota men with alleged connections to white supremacist groups stockpiled weapons and ammunition and made plans to attack the government, minorities and others, a federal affidavit unsealed this week said.

As part of a domestic terrorism investigation in 2010, the FBI scrutinized Samuel James Johnson, 31, of Austin, and Joseph Benjamin Thomas, 42, of Mendota Heights, the affidavit said. Johnson now faces weapons charges in U.S. District Court. Thomas is indicted on drug charges.

"The investigation was based on the fact that the FBI considered them to be legitimate threats and that they wanted to follow through with their plans," said FBI spokesman Kyle Loven. Loven said he couldn't go into specifics because of the indictments.

Johnson used to be a member and the Minnesota leader of the National Socialist Movement, the affidavit said. He started a supremacist group called the Aryan Liberation Movement and tried to round up and train others at bases in Illinois and Minnesota to commit acts of violence against the government and minorities.

The indictment charged Johnson with possession of weapons, including a shotgun and a semi-automatic rifle, and more than a thousand rounds of ammunition. As a felon convicted for armed crimes, he is not allowed to have or own weapons or ammunition.

Thomas told an undercover agent he tried to obtain explosives and automatic weapons to "conduct attacks on left-wing individuals," the affidavit said. The case resulted from an investigation by the FBI's Joint Terrorism Task Force.

In Mower County, Johnson was convicted of robbery, possession of a short-barreled shotgun and sale of a simulated controlled substance in 2007, and attempted robbery in 2000, the indictment said. He was convicted in Hennepin County of felony theft in 1999. The indictment, unsealed Wednesday after the two men's initial appearances in federal court, said Johnson faces at least 15 years in prison and at most a life sentence.

Thomas is charged with possession of and intent to distribute at least 50 grams of methamphetamine starting this February and with distributing at least five grams of the controlled substance. He faces a potential maximum penalty of life in prison for the drug charges, the indictment said.

Kaitlyn Walsh is a University of Minnesota journalism student on assignment for the Star Tribune.