Militants in Iraq have beheaded an Iraqi contractor who they say was working for U.S. forces.

Members of the Ansar al-Sunna Army, the group responsible for the beheading said in a videotaped message on an Islamist website they would kill other Iraqis working with Americans.

Meanwhile, a Jordanian company says it will cease operations in Iraq, as demanded by another group holding one of the firm's employees under a death threat.

In another development, Iraqi police have found the bodies of a beheaded man and a woman who had been shot. Authorities say the unidentified bodies, found south Baghdad, appeared to be those of Westerners. Officials did not say if the victims may have been hostages.