Iraqi insurgents holding four Western hostages threatened in a videotape to kill them if Iraqi detainees are not released by December 8th, Al Jazeera reports this evening.
The tape showed what the television station said were two Canadian hostages receiving food from their captors. An American and a Briton, seized last week, were shown speaking to camera in what the channel said was a call for detainees to be released.
The four were seized in Baghdad last week while working for the the US-based Christian Peacemaker Teams.
They are: Briton, Norman Kember (74) American Tom Fox (54) and Canadians James Loney (41) and Harmeet Singh Sooden (32).
The broadcast came hours after an appeal by the mother and sister of the German woman taken hostage in a separate incident.
Al Jazeera showed Ingrid Hala, mother of kidnapped Susanne Osthoff, urge the captors to "be merciful and graceful".
Ms Osthoff, a 43-year-old archaeologist, disappeared a week ago. Earlier this week, her kidnappers said in a videotaped message that they would kill her if Germany did not end all support for the Iraqi government. Germany helps train Iraqi forces outside Iraq but has ruled out sending troops.
An image from the tape, delivered to Germany's ARD public television in Baghdad, showed what appeared to be Ms Osthoff and her driver sitting on the ground surrounded by three armed, masked men.
"We appeal to you to spare the lives of my innocent sister and her escort," her sister Anja Osthoff said. "My sister has lived for a long time in your country and is devoted to it. She brought sick people medicine. She loves Iraq's great culture."
It was not clear who had carried out the kidnapping of the archaeologist, a converted Muslim who had spent about 15 years working on excavations in Iraq before UN sanctions forced foreign experts out of the country in the late 1980s.
After the March 2003 invasion of Iraq, Ms Osthoff criticised the US military for not preventing widespread looting at archaeological sites. She later volunteered in Iraqi hospitals.
Moqtada al-Sadr, the influential young Iraqi Shi'ite cleric who has helped secure the release of hostages in the past called on Ms kidnappers to set her free.
Sadr said the German woman's kidnapping contradicted "the principles of Islam, which call for respect for women, peace and tolerance", according to German news agency DPA.