The eight were arraigned Wednesday in U.S. District Court in Detroit, including the alleged ringleader, 44-year-old David Brian Stone.
Stone was among nine members of the Hutaree militia arrested after a series of raids in Michigan, Indiana and Ohio. A court document says an undercover FBI agent and a cooperating witness were part of the federal probe.
A hearing to determine if they'll be released on bail began Wednesday for Stone and six others. One suspect's bond hearing will be Thursday.
The ninth suspect was in court in Indiana, and will be arraigned later in Michigan.
Prosecutors have said that members of the Hutaree militia, who had trained themselves to make bombs and use firearms, planned to make a false 911 call, kill responding police officers, then set off a bomb at the funeral to kill many more. Federal officials said they began monitoring the militia last summer and that they believed an attack was planned for April.
"The time had come that we needed to arrest them and ," U.S. Attorney Barbara McQuade said in an interview with The Associated Press.
Stone and his family, who lived in a rural Michigan trailer home, had always been devout, but his private devotions evolved over the years into the Hutaree - a name the group's Web site says they created to mean "Christian warrior."
Stone's former wife Donna, 44, said his personal theology partly destroyed their marriage, but that nevertheless her ex-husband was able to entice her stepson, Joshua Matthew Stone, and her 19-year-old son, David Brian Stone Jr., into the militia that grew out of his faith.
"I honestly feel, and think, their dad never told either of those boys what they were getting into," she said. "This a bunch of garbage, these charges. There is no way my son would do these things."
Donna Stone said she met David Brian Stone in the late 1990s in a grocery store where she worked. He courted her and soon afterward, she and her son, Sean Stetten, moved into his small trailer in Lenawee County, near the Ohio state line. The boys were raised as brothers, and David Brian Stone legally adopted Sean, whose name was changed to David Brian Stone Jr.
Both boys were home-schooled and at night, the family would pray together.
"David would preach out of the Bible," said Donna Stone, who said they were married for about six years. "He would start at the beginning of Genesis and go to Revelations. He didn't get into Revelations because we didn't agree on it. David said it was supposed to be different. He had his own views. That's when I thought it was time for me to go."
The Hutaree Web site quotes several Bible passages and declares: "We believe that one day, as prophecy says, there will be an Anti-Christ. ... Jesus wanted us to be ready to defend ourselves using the sword and stay alive using equipment."
McQuade downplayed the role religious ideology played in the group's alleged plans, saying the "most troubling" finding of their investigation into the Hutaree were the details of their alleged plot.
"What we were focused on here is their conduct, not on their religion. And what they have talked about is being very anti-government," McQuade said Tuesday. "They fear this `new world order' and they thought that it was their job to fight against government - the federal government in particular."
The group was preparing to carry out an attack sometime in April, prosecutors said, after months of paramilitary training that began in 2008 and included learning how to shoot guns and make bombs. Authorities seized guns in the raids but would not say whether they found explosives.
McQuade declined to discuss other specifics, including how the group originally came to the attention of authorities or how agents learned about the alleged plans for an attack in April.