Video footage posted on the Internet showed five armed and masked men standing around the hostage, identified as Eugene Armstrong, with the banner of al-Zarqawi's Al-Tawhid wa Al-Jihad group hanging in the background.
The footage then showed a masked man sawing off the hostage's head with a knife. Al-Zarqawi has claimed he personally carried out the beheading, according to AP.
The militants said Armstrong was killed because U.S. authorities had failed to meet a 48-hour deadline set on 18 September for the release of female Iraqi prisoners being held in Iraqi jails.
Another 24-hour deadline was set for the release of female prisoners, or U.S. citizen Jack Hensley and Briton Kenneth Bigley -- who were abducted along with Armstrong from their Baghdad home on 16 September -- would be killed.
The U.S. military has denied holding any female prisoners in the prisons specified by the militants, although it has acknowledged holding two female Iraqis accused of working on deposed President Saddam Hussein's weapons program.
Also today, gunmen killed a Muslim cleric in Baghdad, the second attack on a cleric belonging to an influential association of Sunni clerics in as many days.
The attack came as 18 kidnapped Iraqi National Guard members were freed by their captors following a call by a radical Shi'ite Muslim cleric.
Meanwhile, guerrillas attacked a U.S. patrol north of Baghdad, killing one U.S. soldier. U.S. warplanes struck in the insurgent stronghold of Al-Fallujah, west of the capital, killing two people. A car packed with explosives blew up in a residential neighborhood in the northern city of Mosul, killing its driver and two people.
The footage then showed a masked man sawing off the hostage's head with a knife. Al-Zarqawi has claimed he personally carried out the beheading, according to AP.
The militants said Armstrong was killed because U.S. authorities had failed to meet a 48-hour deadline set on 18 September for the release of female Iraqi prisoners being held in Iraqi jails.
Another 24-hour deadline was set for the release of female prisoners, or U.S. citizen Jack Hensley and Briton Kenneth Bigley -- who were abducted along with Armstrong from their Baghdad home on 16 September -- would be killed.
The U.S. military has denied holding any female prisoners in the prisons specified by the militants, although it has acknowledged holding two female Iraqis accused of working on deposed President Saddam Hussein's weapons program.
Also today, gunmen killed a Muslim cleric in Baghdad, the second attack on a cleric belonging to an influential association of Sunni clerics in as many days.
The attack came as 18 kidnapped Iraqi National Guard members were freed by their captors following a call by a radical Shi'ite Muslim cleric.
Meanwhile, guerrillas attacked a U.S. patrol north of Baghdad, killing one U.S. soldier. U.S. warplanes struck in the insurgent stronghold of Al-Fallujah, west of the capital, killing two people. A car packed with explosives blew up in a residential neighborhood in the northern city of Mosul, killing its driver and two people.
