Police in Wichita, Kan., are investigating red swastikas that a vandal painted on the storefront office of U.S. Sen. Pat Roberts.

KSNW-TV reports the Kansas Republican’s staff arrived Monday to find the swastikas painted on the front of the office and on a back door.

Police Lt. Joe Schroeder says the FBI is working on the case with Wichita police because it’s a federal office.

KSNW reports a similar incident happened at Roberts’ office a few months ago.