The Associated Press reported that Chad Allen Williams, 46, was arrested by the Bureau of Alcohol, Tobacco and Firearms on Friday after searching his home.
Mr Williams is accused of placing a pipe bomb in a Des Moines suburb, which was discovered by an 8-year-old girl who was playing outside. The bomb was disarmed by the Iowa Fire Marshal's Office without incident.
Investigators found Mr Williams' workbench in his garage along with fireworks, a spool of fuse, a bottle of vehicle lubricant, zip ties, screws, nuts and metal wall anchors, according to court documents.
Mr Williams told investigators that he made the bombs by filling the vehicle additive bottle with BBs and metal items like nuts and bolts, and taping it to two firework shells. He said he lit the fuse and dropped it off but did not hear the bomb go off.
He has been charged with making and possessing an unregistered explosive device and is being held in a jail in Polk County until his hearing next week.
Another pipe bomb was found on 1 March outside a polling place in nearby Ankeny, only two miles from where Mr Williams' bomb was found.
However, investigators do not believe that Mr Williams built that device.
The discovery of that device by a couple walking their dog sparked a temporary evacuation of the polling place, which was later re-opened.
That bomb was also disarmed by the fire marshal's office, which said it could have caused major damage had it been detonated.
Residents in Ankeny also reported hearing explosions on 2 April, 12 May and 7 June. Mr Williams has not been implicated in any of those incidents.