Four elderly US men sat in federal court in the southern state of Georgia facing accusations that they were militia members intent on attacking US government offices and plotting targeted assassinations. The men, ranging in age from 65 to 73, were arrested by FBI agents Tuesday on charges \"relating to plans to obtain an unregistered explosive device and silencer and to manufacture the biological toxin, ricin,\" the Justice Department said. In their first court hearing Wednesday in Gainesville, Georgia the men appeared in leg shackles and orange prison jumpsuits and asked the court to assign them an attorney. An FBI informant infiltrated meetings that the suspects -- described in the affidavit as \"members of a fringe group of a known militia organization\" -- had held starting in March to discuss the attacks. At one meeting Frederick Thomas, 73, \"began discussing overt and covert operations for the group,\" the undercover FBI informant said in the affidavit. Thomas mentioned a novel \"in which an anti-government group killed a large number of federal Department of Justice attorneys, and then he stated, \'Now of course, that\'s just fiction! but that\'s a damn good idea,\'\" the informant said. Thomas spoke of the need to acquire more weapons, ammunition, food, and survival gear, and suggested buying silencers for handguns. Thomas even proposed destroying a building like Timothy McVeigh, the US terrorist who set a truck bomb outside a federal building in Oklahoma City in 1995 that killed 168 people. In March and April, Thomas and two other suspects -- Dan Roberts, 67, and Ray Adams, 65 -- discussed targeting government officials, including Internal Revenue Service (IRS) agents. Adams, who had worked as a lab technician at the US Department of Agriculture, is accused of trying to help the fourth suspect, Samuel Crump, 68, try to obtain ricin for the attacks. \"While many are focused on the threat posed by international violent extremists, this case demonstrates that we must also remain vigilant in protecting our country from citizens within our own borders who threaten our safety and security,\" said Sally Quillian Yates, the US attorney for the northern district of Georgia.