The militant group led by al-Qaida ally Abu Musab al-Zarqawi posted a gruesome video on a Web site Monday showing the decapitation of a man identified as American civil engineer Eugene Armstrong and said a second hostage _ either an American or a Briton _ would be killed in 24 hours.
The grisly beheading was the latest killing in a particularly violent month in Iraq, with more than 300 people dead in insurgent attacks and U.S. military strikes over the past seven days. Earlier Monday, gunmen in Baghdad assassinated two clerics from a powerful Sunni Muslim group that has served as a mediator to release hostages.
The video of the beheading of the man believed to be Armstrong, whose age is not known, surfaced soon after the expiration of a 48-hour deadline set earlier by Zarqawi's Tawhid and Jihad group for the beheading of the three civil engineers. The men _ Armstrong, American Jack Hensley and Briton Kenneth Bigley _ were abducted Thursday from their home in Baghdad.
A militant whose voice resembled Zarqawi's read a statement in the video saying the next hostage would be killed in 24 hours unless all female Muslim prisoners are released from U.S. military jails.
The Associated Press, quoting a U.S. official in Washington who spoke on condition of anonymity, reported that Armstrong's body had been recovered, but the official would provide no information about where or when.
The taped beheading appears to be of Armstrong, but the CIA is still reviewing the tape to be sure, the official said.
The nine-minute tape, posted on a Web site used by Islamic militants, showed a man seated on the floor, blindfolded and wearing an orange jumpsuit _ similar to the orange uniform worn by prisoners at the U.S. naval base in Guantanamo Bay, Cuba _ with his hands bound behind his back. Five militants dressed in black stood behind him, four of them armed with assault rifles, before a black Tawhid and Jihad banner.
The militant in the center read a statement, as the hostage rocked back and forth and side to side where he sat. After finishing, the militant pulled a knife and murdered him.
Tawhid and Jihad _ Arabic for "Monotheism and Holy War" _ has claimed responsibility for killing at least six hostages, including Armstrong and another American, Nicholas Berg, who was abducted in April. The group has also said it is behind a number of bombings and gun attacks.
In a video Saturday setting the 48-hour deadline, the militants demanded the release of female Iraqi prisoners detained by the U.S. military. The military says it is holding two women with ties to Saddam Hussein's regime: Dr. Rihab Rashid Taha, a scientist who became known as "Dr. Germ" for helping Iraq make weapons out of anthrax, and a biotech researcher. But there may be women held as common criminals.
They said no women were being held at the U.S. military prison at Abu Ghraib, west of Baghdad, where American soldiers were photographed sexually humiliating male prisoners.
The militant on the video called President Bush "a dog" and addressed him, saying: "Now, you have people who love death just like you love life. Killing for the sake of God is their best wish, getting to your soldiers and allies are their happiest moments, and cutting the heads of the criminal infidels is implementing the orders of our lord."
Armstrong grew up in Hillsdale, Mich., but left the area around 1990. His brother, Frank, still lives there. Armstrong's work in construction took him around the world; he lived in Thailand with his wife before going to Iraq.
The other American hostage, Jack Hensley, 48, made his home in Marietta, Ga., with his wife, Patty, and their 13-year-old daughter. Kidnapped with the Americans was Briton Kenneth Bigley, 62. All three worked for Gulf Services Co. of the United Arab Emirates.
In a statement released after the video was posted, Armstrong's family said: "This is what we did not want to hear. We are praying for Jack Hensley and Kenneth Bigley and their families."
Army Spc. Keith M. Maupin, 20, of Batavia, Ohio, is officially listed by the military as missing. Maupin disappeared in Iraq on April 9 after an attack on a fuel convoy.
Also missing from that convoy attack are contract truckers William Bradley and Timothy Bell, both Americans.
More than 130 foreigners have been kidnapped in Iraq, some for ransoms, and at least 26 have been executed. At least five other Westerners are being held hostage, including an Iraqi-American man, two female Italian aid workers and two French reporters.
On Monday, kidnappers released a group of 18 abducted Iraqi National Guard members after renegade Shiite cleric Muqtada al-Sadr called for their release, Sadr aide Nail al-Kabi told the Associated Press.
North of Baghdad, insurgents attacked a U.S. patrol near the town of Sharqat, killing an American soldier.
The United States has blamed Zarqawi, a former convict who reportedly converted to militant Islam while in prison, for much of the violence. A $25-million reward has been offered for information leading to his capture. For more than a week, U.S. fighter jets have made bombing runs in the restive city of Fallujah, where U.S. officials believe Zarqawi has his base of operations.
U.S. forces bombed a construction site in Fallujah about 2 p.m. Monday, according to the U.S. military. The attack killed five Iraqis and injured seven, according to hospital officials and witnesses who disputed U.S. military claims that equipment at the site was used by insurgents to build fighting positions.
A Web site statement posted Monday in the name of Zarqawi's Tawhid and Jihad group condemned the killing of the two Sunni Muslim clerics in Baghdad.
Gunmen shot and killed Sheik Mohammed Jadoa al-Janabi as he entered a mosque in the capital's predominantly Shiite al-Baya neighborhood to perform noon prayers Monday.
The previous night, gunmen kidnapped Sheik Hazem al-Zeidi and two of his bodyguards as he left a mosque in a Shiite neighborhood, Sadr City. The bodyguards were released Monday.
The two clerics belonged to the Association of Muslim Scholars, a grouping of conservative clerics that opposes the U.S. presence in Iraq and has emerged as a powerful representative of Iraq's Sunni minority.
Information from the Washington Post was used in this report.