An Islamic militant group in Iraq says it has taken a U.S. soldier hostage and is threatening to kill him unless Iraqis held in U.S. prisons are freed within 72 hours.

A group calling itself the Mujahedeen Squadrons made the kidnapping claim and demand in a statement posted on an Islamist website Tuesday, along with a photograph of the alleged captive.

The Internet statement's authenticity could not be verified, and the U.S. military said it could not confirm the claim.

Some information for this report provided by Reuters and AFP.