A video released on an Islamic website Monday showed the beheading of a U.S. hostage. A statement on the website said the hostage, identified as American construction contractor Eugene Armstrong, was beheaded by the Tawhid and Jihad group's chief, Abu Musab al-Zarqawi. Al-Zarqawi is suspected of being the al-Qaeda terrorist network's leader in Iraq and has been accused of numerous beheadings and terrorist attacks there. The video showed Armstrong, clothed in an orange jumpsuit, screaming as his killer sawed at his neck with a knife. The group said it would give the U.S. military another 24 hours to fulfil its demand that all Iraqi women prisoners be released. Otherwise, Briton Kenneth Bigley and another American, Jack Hensley, who were kidnapped at the same time as Armstrong, would also to be killed, it said. After the three men were kidnapped Thursday in Baghdad, Tawhid and Jihad gave the United States 48 hours to comply with its demand. The families of the three men released statement on Arab television news networks pleading for their loved ones' release.