Baghdad ? A private security guard fatally shot an Iraqi taxi driver, Iraqi officials said Monday, in the latest incident involving what Iraqis believe are unprovoked killings by contractors hired to protect Americans.

A spokesman for DynCorp International, a Falls Church, Va.-based company, said one of its security teams opened fire Saturday to disable a vehicle in Baghdad after it approached a convoy in a threatening manner.

“Our team had reported that they believed no one was injured. So although there were conflicting reports, we are trying to determine if the incidents are one and the same,” said Gregory Lagana, DynCorp’s senior vice president for communications.