Police say they've arrested a man who intentionally assaulted U.S. Sen. Rand Paul, causing a minor injury.

Rene Boucher, 59, of Bowling Green, is charged with one count of fourth-degree assault and is being held in the Warren County Detention Center, according to a news release from Kentucky State Police.

Police responded to a report of an assault at Paul's Warren County, Ky., residence just before 3:30 p.m. Friday. They determined Boucher had intentionally assaulted the junior senator, according to the release. It was not immediately clear what injury Paul suffered.

Rene Boucher's mugshot from the Warren County (Kentucky) jail.

A spokeswoman for Paul's office said in an email that the senator was "blindsided."

"Senator Paul was blindsided and the victim of an assault," the spokeswoman said. "The assailant was arrested and it is now a matter for the police. Senator Paul is fine."

The investigation is ongoing.

State Police spokesman Jeremiah Hodges said the FBI was on scene to investigate whether the assault was politically motivated, but he was unable to elaborate on the status of that investigation.

David Habich, a spokesman for the FBI, said the agency was aware of the incident concerning Paul. 

"We are working with our state and local partners to determine if there was a violation of federal law," Habich said. 

Voter records from March 2017 show Rene Boucher had registered as a Democrat.

A court website shows that Boucher was booked Friday night just before 9 p.m. He's being held on $5,000 bond and there is no court date set.