The captors of a kidnapped US journalist in Iraq have threatened to kill her unless US forces release all female prisoners in the country. On Tuesday, the Arabic television network Al-Jazeera broadcast a videotape of Jill Carroll, a 28-year old freelance reporter working for the Christian Science Monitor. It was the first time she has been seen since she was seized in Baghdad earlier this month. The video contained no audio. Al-Jazeera said the captors identified themselves as members the previously unknown group the “Brigades of Vengeance.” The group gave a 72-hour deadline for the US to comply with their demand.