On the video, the victim identifies himself as Durmus Kumdereli. Speaking in Turkish, he says he was transporting goods to an American military base in Mosul. Arabic subtitles accompanied his words.

Afterward, a black screen reading ''the execution'' appears, followed by warnings from masked, armed militants to foreign drivers, and grisly footage of the beheading.

The authenticity of the video, which was digitally dated Aug. 17, could not be verified. It was posted on the Web site known for carrying statements from Tawhid and Jihad, a group led by Jordanian militant Abu Musab al-Zarqawi that has beheaded other foreign hostages.

The Web site had been inaccessible in recent days before resurfacing Monday at a new address.

In Ankara, a Turkish Foreign Ministry official, speaking on condition of anonymity, said the ministry was aware of the video but was unable to confirm Kumdereli's death.

Kumdereli was abducted Aug. 14 outside Mosul after delivering water to a U.S. base in Baghdad. Another Turkish driver, Mustafa Koksal, was taken hostage with him; four days later, the Turkish government said he had been rescued.

The man who identified himself as Kumdereli, reading from a piece of paper, was standing next to another hostage. The militants identified the second man only as another driver whom they decided to release.