A minor altercation occurred Wednesday night involving Rep. Sean P. Duffy, R-Wis., according to Capitol Hill sources.

Duffy’s office is confirming that “a minor incident happened last night as the congressman was walking to the Capitol for final votes.”

The final vote series occurred shortly after 6 p.m. Wednesday.

“A random individual, unknown to the congressman, began screaming at him and grabbed his arm,” said spokeswoman Cassie Smedile in a Thursday morning statement. “Mr. Duffy was unharmed. He reported the incident in compliance with House security procedures. Congressman Duffy has requested no further action be taken and there will be no further comment on the matter at this time.”

The confrontation may have stemmed from frustration over the federal government shutdown, according to sources.

Capitol Police are investigating a report of an assault on a member of Congress in the Longworth House Office Building, according to Kimberly Schneider, a public information officer for the department.