(CNN) -- Three self-proclaimed anarchists who plotted to blow up a bridge with plastic explosives pleaded guilty Wednesday in federal court in Cleveland.
After an undercover operation, the FBI arrested five suspects in the plot on April 30 of this year. The FBI called the plan an act of domestic terrorism.
Ohio defendants Brandon Baxter, 20, of Lakewood, and Connor Stevens, 20, of Berea admitted their roles in a plan to remotely detonate improvised devices containing C-4 explosives, with the goal of toppling a bridge over Cuyahoga Valley National Park near Cleveland, according to Northern Ohio District U.S. Attorney Steven Dettelbach.
An Indianapolis conspirator, Douglas Wright, 26, also pleaded guilty Wednesday to the same charges -- conspiracy to use a weapon of mass destruction, attempted use of a weapon of mass destruction and use of an explosive device to destroy property used in interstate commerce, said Dettelbach and Stephen Anthony, who heads the FBI field division in Cleveland.
A fourth defendant, Anthony Hayne, 35, of Cleveland, pleaded guilty to the same charges in July and faces a recommended sentence of 14 to 19 years in prison.
The fifth defendant, Ohio native Joshua Stafford, is undergoing examinations and awaits a competency hearing after he attempted to take his own life, according to an official with the U.S. attorney's office in Cleveland.
Authorities said the defendants had considered several targets during a period of several months before settling on the bridge connecting Brecksville and Sagamore Hills in Ohio.
U.S. attorney's office spokesman Mike Tobin said the three defendants who pleaded guilty Wednesday will face prison terms of from 30 years to life when they are sentenced in early November.