President Barack Obama's campaign building in Des Moines, Iowa, was vandalized with the words "Muslim Lier" (intended to be "Liar"), spray-painted on a large banner.
The blue banner is 16 by 8 feet and hangs on the south side of the building at 2307 Hubbell Ave. The words were written with red spray paint, police said.
The vandalism occurred sometime between 11:30 p.m. Wednesday and 10 a.m. Thursday, when it was discovered, police reports show.
The same message was reportedly spray painted near the Iowa State Fairgrounds earlier in the week.
The damage was estimated at $500.
Dating back to his 2008 campaign, a faction of Americans have falsely believed that Obama is a Muslim, even though he has openly discussed his Christian faith. According to a poll released in July, 30 percent of Republicans and 34 percent of conservative Republicans identified the president as a Muslim.
Last week, Madonna created a stir when she told fans at a concert, "We have a black Muslim in the White House." The singer later clarified that she was simply being ironic.
A request for comment was not immediately returned by the Obama campaign's Iowa office.