Atlanta (CNN) -- Prosecutors have released a recording of a man described as the leader of a militia group in Georgia talking about shooting "IRS and ATF" agents and other officials.
"I could shoot IRS and ATF all day long. All the judges and the DOJ (Department of Justice), and the attorneys and prosecutors," said the man, described as the leader of a militia organization called Covert Group.
The U.S. attorney's office in Atlanta released audio recordings Monday of four men charged with plotting to purchase unregistered weapons and explosives to kill government workers, while also allegedly planning to produce a deadly bio-toxin to kill indiscriminately.
Dan Roberts, 67; Frederick Thomas, 73; Samuel Crump, 68; and Ray Adams, 65, will remain in custody until they stand trial, officials say.
According to prosecutors, the audio recordings were made by confidential informants who posed as sympathizers with the north Georgia militia group and recorded the men -- at times with their full knowledge.
Prosecutors said the public was never in imminent danger from the plot, but the men were in the process of buying explosives when agents moved in to arrest them.
The recorded statements will be used in court as proof the men were serious about the alleged terror plot, prosecutors said.
Thomas allegedly states in one of the recordings, "We know what we want to do. We know how to do it. What we need to do is to prepare to do it. So that's what we're doing now. Making the preparations, getting what we need so that when we go about doing it we are equipped."
During a group meeting, Thomas is also heard allegedly asking his fellow members, "Are you committed? I am. To taking action. If we get a militia unit going large enough, are they committed to taking action? Will they take a life? All right, so, who's willing to take a life?"
Prosecutors say the men planned to target buildings in Atlanta used by the FBI, the IRS and the Bureau of Alcohol, Tobacco, Firearms and Explosives. They also allegedly had plans to produce the highly lethal toxin ricin, and to spread it on highways in several major U.S. cities sometime within the next year.
All four defendants pleaded not guilty in court last week, but federal magistrate Judge Susan Cole denied bond after listening to preliminary hearings.
Roberts' court-appointed attorney, Michael Trost, said he plans to file an appeal of the outcome with a district judge. "I think they got a fair hearing, but I respectfully disagree with the judge," Trost told CNN.
CNN's Vivian Kuo and John Murgatroyd contributed to this report.