A Nazi flag was found raised on the flagpole in a public park in Laramie, Wyoming, on Monday, police told BuzzFeed News.
Police were alerted by a local resident who said the American flag that flies in the the town's Washington Park had been taken down, with the Nazi flag hoisted instead.
"We responded and took down the Nazi flag and raised the American flag to its rightful place," Chief of Police Dale Stalder said.
According to the Laramie Boomerang, the American flag "was crumpled and shoved into a corner of the band shell" in Washington Park.
Police reportedly folded the American flag and restored it to the flagpole.
"We have not identified the person or persons who did the very disrespectful act," Stalder said.
The incident is not a criminal act, he said, as the American flag was not vandalized or stolen.
Still, they are investigating, he said.
"We are attempting to find out who did this because it is so upsetting at a community level," Stalder said.
In a statement to BuzzFeed News, local Anti-Defamation League leader Jeremy Shaver thanked police for investigating the incident.
"It is appalling and outrageous that anyone would cast aside the American flag in a public park and replace it with an ugly symbol of the Nazi regime," said Shaver. "We commend the responding officers with the Laramie Police Department for acting in such a respectful and professional manner on scene."