Federal authorities charged a Madison man Friday with making a telephone threat in February to blow up the offices of the Democratic Party of Wisconsin, among more than 100 calls, many threatening, that he allegedly placed to the office this year.

William O. Diederich, 61, repeatedly threatened to shoot Democrats and those supporting the recall of Gov. Scott Walker in phone calls he made to the Democratic Party's office at 110 King St. in January, February and March, according to an affidavit by FBI agent Joseph Lavelle, filed in U.S. District Court in Madison.

Diederich was arrested earlier Friday at a residence near Pickerel in Langlade County, the federal Department of Justice said. He appeared briefly in federal court on Friday and was ordered to be kept in custody at least until another hearing on Wednesday.

If convicted of making the bomb threat, Diederich faces up to 10 years in prison.

On Feb. 24, the affidavit states, Diederich left a voice mail message stating that when the building explodes, the bombings of Sterling Hall on the UW-Madison campus and the federal building in Oklahoma City will "seem like a firecracker compared to what's gonna happen to you people."

The message states that the building was going to blow up "one of these days."