Baghdad ? An Iraqi insurgent group Monday posted a video on the Internet showing what it said was the execution of an American contractor abducted earlier this month.

In the video, a man with his back to the camera fires five shots into the back of another man, kneeling and blindfolded, who is identified in a caption as Ronald Schulz, a “security adviser” to the Housing Ministry. Split-screen images showed Schulz’s passport and a previously broadcast image of him with his hands bound behind him.

A logo of the Islamic Army in Iraq, which said Dec. 8 that it had executed Schulz, appears in a corner of the screen. No faces are shown on the portion of the video that includes the shooting.

Elizabeth Colton, a U.S. Embassy spokeswoman, said in a statement: “We have seen reports of a videotape showing what appears to be the vicious killing of an American citizen hostage in Iraq. We are unable to confirm the authenticity of the videotape, or the identity of the individual in the video. We continue to work with Iraqi authorities to locate those Americans being held hostage in Iraq.”

Schulz, a native of South Dakota who lived recently in Alaska, is one of at least eight foreigners abducted here since late November, after several months in which such incidents were rare. Friends and family have said he is an electrician and not a security specialist.

Sunday, German authorities announced the release of archaeologist and aid worker Susanne Osthoff, who had been kidnapped along with her driver three weeks earlier.

The status of four members of the organization Christian Peacemaker Teams – two Canadians, a British citizen and an American – who were abducted one day after Osthoff is unknown. A French engineer reportedly also was taken captive near his Baghdad home this month.