Two billboards in which images of Native Americans are used to make a gun rights argument are causing a stir with some Colorado residents who say the image is offensive and insensitive.

The billboards in this northern Colorado city show three men dressed in traditional Native American attire and the words "Turn in your arms. The government will take care of you."

Matt Wells, an account executive with Lamar Advertising in Denver, said Monday that a group of local residents purchased the space.

"They have asked to remain anonymous," he said.

He also refused to disclose the cost but said the billboards are only appearing in the Greeley area. Wells said he has not received any complaints so far.