Three north Georgia men have been sentenced to prison for conspiring to use “weapons of mass destruction” against federal government agencies, the U.S. Attorney’s Office announced Friday.

Brian Cannon, Terry Peace and Cory Williamson, who were living in Rome, planned “to attack critical infrastructure to motivate militia groups to rise up,” against government officials, federal prosecutors said.

Each man was sentenced to 12 years in prison.

“In this case, anti-government ideology and rhetoric morphed into dangerous extremism and led these defendants to arm themselves and travel to a meeting to pick up pipe bombs and other explosives intended for attacks,” U.S. Attorney John Horn said in a news release. “The attacks planned by the defendants, while rare, posed a serious threat to not only the safety of our public servants, but also all other members of the community.”

The scheme was unveiled in January and February 2014 when the three men participated in Internet chat rooms used by militia members and others with an anti-government ideology, Horn said. The men discussed attacks on the Transportation Security Administration, the Department of Homeland Security and the Federal Emergency Management Agency, Horn said.

One of the participants in the Internet chat informed the FBI and worked undercover in the investigation. Peace asked the cooperating witness to provide 12 pipe bombs and two thermite devices for the attack and took delivery of dummy devices Feb. 15, 2014 in Cartersville, Horn said.

Peace said he wanted the pipe bombs designed for “maximum fragmentation,” Horn said.

Cannon, 37, Peace, 47, and Williamson, 29, were all sentenced to 12 years in prison to be followed by five years of supervised release. They also must perform 100 hours of community service.

They pleaded guilty in May.