Four American security contractors and an Austrian remain in captivity after their kidnapping in southern Iraq six weeks ago, the US Embassy said Thursday. The men went missing Nov. 16 when a large convoy of trucks being escorted by their Crescent Security Group was hijacked on a highway near Safwan, a city on the border with Kuwait. Suspected militiamen dressed in Iraqi police uniforms ambushed the convoy, taking 14 hostages, including the five security guards, and nine truck drivers who were later released. Lou Fintor, a spokesman for the US Embassy in Baghdad, said the Americans remain in captivity. "At this time, US officials believe the American citizens are still being held by their captors. The State Department continues to be in touch with the families of the US citizens. We strongly condemn the kidnapping and call on the hostage-takers to release these people immediately," Fintor said.