The images of soldiers were taken in 2004 and 2005 by New York photographer Suzanne Opton while the soldiers were between tours of duty in Iraq and Afghanistan, as a part of a series called "Soldier Billboard Project."

CBS Outdoor said the images cannot be displayed on one of its billboard in downtown St. Paul, Minn., Opton said in a statement Wednesday.

"The reason we have advised you that we cannot post these as billboards is that out-of-context (neither in a museum setting or Web site) the images, as stand-alone highway or city billboards, appear to be deceased soldiers," wrote CBS Outdoor Executive Vice President of Marketing Jodi Senese in an e-mail to Opton.

Senses added that the billboards "could be perceived as being disrespectful to the men and women in our armed forces."

In a statement, Opton said the soldiers are "very much alive."

She said, "Far from being disrespectful, the images are vivid reminders of the hundreds of thousands of soldiers serving the country. The series simply shows them in a more vulnerable pose than the public is accustomed."