The victim said he was an American from Philadelphia
An Islamic militant website has shown a video purporting to show the beheading of an American in Iraq.
The video - the contents of which could not be verified - showed five men in headscarves and ski masks cutting off the man's head with a knife.
Moments earlier, the victim said he was an American from Philadelphia.
The group, thought to be linked to al-Qaeda, said it was carrying out the execution in retaliation for the abuse of Iraqi prisoners by US soldiers.
The poor-quality tape - shown on the Muntada al-Ansar site - began with the victim, bound and wearing an orange jumpsuit, sitting on the floor with five masked men behind him.
The victim identified himself as Nick Berg, a US contractor whose body was found near a highway overpass in Baghdad on Saturday.
One of the masked men read out a statement, saying they had offered to exchange the man for inmates of Abu Ghraib prison but the coalition authorities refused.
They then pulled the man to the side and put a knife to his neck.
The man screamed as he was executed.
His killers shouted "Allah is great" before holding what appeared to be a head up to the camera.
May 13, 2004
Video 'shows US man beheaded'
The victim said he was an American from Philadelphia
An Islamic militant website has shown a video apparently showing the beheading of an American in Iraq.
The video showed five men in headscarves and ski masks cutting off the man's head with a knife.
Moments earlier the victim, bound and dressed in an orange jumpsuit, said he was an American from Philadelphia.
The group, thought to be linked to al-Qaeda, said it was carrying out the killing in retaliation for the abuse of Iraqi prisoners by US soldiers.
We will pursue those who are responsible and bring them to justice
Scott McClellan
White House spokesman
The poor-quality tape - shown on the Muntada al-Ansar site - began with the victim sitting on the floor with five masked men behind him.
It was titled "Abu Musab al-Zarqawi shown slaughtering an American".
The CIA is said to be checking to see whether Zarqawi - a senior al-Qaeda operative accused of masterminding multiple bomb attacks against US forces in Iraq - was actually in the video.
Washington vowed to find the killers.
"It shows the true nature of the enemies of freedom," said White House spokesman Scott McClellan.
"They have no regard for the lives of innocent men, women and children. We will pursue those who are responsible and bring them to justice."
However, the victim's father said the US authorities were indirectly to blame for his death for failing to get him safely out of the country.
'Devilish scorn'
The victim identified himself as Nick Berg, a US civilian contractor. His body was found near a highway overpass in Baghdad on Saturday.
Details of Nick's death added to the pain of his grieving family
"My father's name is Michael, my mother's name is Suzanne," the man said on the video. "I have a brother and sister, David and Sarah. I live in... Philadelphia."
One of the masked men read out a statement, saying they had offered to exchange the man for inmates of Abu Ghraib prison but the coalition authorities refused.
"How can a free Muslim sleep well as he sees Islam slaughtered and its dignity bleeding, and the pictures of shame and the news of the devilish scorn of the people of Islam - men and women - in the prison of Abu Ghraib?" he said.
"You will not receive anything from us but coffins after coffins... slaughtered in this way."
The statement also threatened US President George W Bush, saying he would regret the day he stepped into Iraq.
It described Pakistani President Pervez Musharraf as a "traitor agent".
Disappearance
After reading the statement, they pulled the man to the side and put a knife to his neck.
The man screamed as he was killed.
His killers shouted "Allah is great" before holding what appeared to be a head up to the camera.
The 26-year-old Mr Berg, who owned a communications equipment company, was involved in rebuilding antennas in Iraq before he disappeared on 9 April.
But he went missing prior to that, and was later found to have been arrested at an Iraqi checkpoint in Mosul and held in an Iraqi jail with Iraqi prisoners for 13 days, his father told American TV on Tuesday morning, before the video was released.
Michael Berg said the US authorities were indirectly responsible for his death, by failing to secure his release and thereby causing him to miss his flight home on 30 March.
"He would have missed the escalation if they had let him go," he said.
The Berg family declined further comment after receiving news of the video.
Berg video website shut down
By Jonathan Kent
BBC, Kuala Lumpur
The internet website that first posted video footage of an American contractor being beheaded in Iraq has been closed.
The Malaysian server for the site said it took action after the huge numbers of people trying to view the video overloaded its systems.
The company said it had been unaware of the site's contents, but would have acted sooner if it had known.
The graphic images of 26-year-old Nicholas Berg's death prompted shock and outrage the world over.
They also prompted thousands upon thousands of people to log on to the internet so they could see for themselves the entire event in all its horror.
The video was stored on a computer server belonging to a Malaysian web hosting company, Acme Commerce Sendirian Berhad.
The server had been leased to the creators of the site, Al-ansar.biz. They first put the film on the net, and are thought to have links to al-Qaeda.
Acme Commerce's business manager told the BBC that the volume of traffic to that one address was so great that it jammed connections to hundreds of other servers operated by the company.
Though the decision to close the website was a technical one, he said the company would have acted earlier on moral grounds if it had known the site's contents.
He said Acme had no wish to be associated with any group which had possible al-Qaeda connections, or which distributed such gruesome pictures.
Malaysia's opposition leader has called for an investigation into the possibility that the country is hosting what he called a "master network of international terrorist websites".
Zarqawi is said to be behind many attacks against coalition troops
Al-Qaeda suspect Abu Musab al-Zarqawi probably carried out the beheading of US contractor Nicholas Berg in Iraq, CIA officials say.
US intelligence agencies have been analysing the video of the execution shown on a Malaysian-based website.
It was highly probable that it was Zarqawi who wielded the knife, an unnamed CIA official said.
The graphic images of the 26-year-old's death prompted shock and outrage all over the world.
CIA assesses with high probability that the speaker on the tape is Abu Musab al-Zarqawi, and that person is shown decapitating American citizen Nicholas Berg
Unnamed CIA official
Profile: Abu Musab al-Zarqawi
His killers said they were avenging the abuse of Iraqi detainees by US forces in Iraq.
They had offered to exchange him for inmates at Baghdad's Abu Ghraib prison but the coalition authorities had, they said, refused.
Violence 'plotted'
The grainy pictures of the murder were preceded by a caption announcing that the Jordanian-born Zarqawi would carry out the killing.
Berg's execution has caused horror across the world
"After the intelligence community conducted a technical analysis of the... video, the CIA assesses with high probability that the speaker on the tape is Abu Musab al-Zarqawi, and that person is shown decapitating American citizen Nicholas Berg," a CIA official said.
In February, US officials in Iraq said they had uncovered what they believed to be a plot by Zarqawi to foment sectarian violence in the country.
They believe he was behind a number of high-profile attacks and have offered a $10m reward for information leading to his death or capture.
FBI visited Berg
Mr Berg - a telecoms worker - was arrested two months ago in Iraq.
According to his family, he was held for 13 days before being released without charge. It is not clear who arrested and held him.
Agents for the American FBI say they interviewed him when he was in the custody of Iraqi police in the northern city of Mosul, but other reports say he was not held by the Iraqis.
Mr Berg's father, Michael, said his son had been trying to come home before the violence in Iraq worsened.
The family have partly blamed the US-led coalition for creating the circumstances in which he was abducted, about a month ago.
They were holding a memorial service on Friday.
May 14, 2004
Other U.S. officials said this week that Iraqi police arrested Berg in Mosul on March 24, because they believed he may have been involved in "suspicious activities." Berg, for his part, told friends that he was arrested in Mosul because he had an Israeli stamp in his passport.
Berg confirmed that U.S. investigators visited him in Mosul, telling his parent in an e-mail message that was given to The New York Times that federal agents had questioned him about whether he had ever built a pipe bomb or had been in Iran.
The police chief in Mosul, Maj. Gen. Mohammed Khair al-Barhawi, said his department never arrested Berg and that he had no knowledge of the case.
Ashcroft said FBI agents and officials of the U.S.-led coalition in Iraq encouraged Berg to accept a U.S. offer to arrange safe passage out of Iraq, but he declined it.
Moreover, Ashcroft said, when Berg was released by the Iraqi police, "he refused government offers to advise his family and friends of his status."
'It was an adventure'
Berg's friends said his arrest seemed not to dent an optimism about his venture in Iraq that bordered on dangerous naivete.
"I was worried for him. He was too white. He would walk around the streets in a sleeveless T-shirt, ripped jeans," said a journalist who said he was Berg's friend but spoke on condition of anonymity. "He looked military."
Duke, the consultant, said he saw Berg on April 9, the day before he disappeared. He said that although Berg was planning to return to the United States, his optimism about his prospects in Iraq was undimmed.
"He came over and we had a few beers and talked about his future, how this was going to be an opportunity for a guy in the tower business," Duke said.
May 14: The DJs, known as Marconi and Tiny, were fired Thursday by KNRK-FM, which aired an apology. Dave Northfield of NBC affiliate KGW-TV reports.
MSNBC
Oregon DJs fired
for playing tape
of Berg's death
Radio figures cracked jokes about beheading
The Associated Press
Updated: 4:27 p.m. ET May 14, 2004PORTLAND, Ore. - Two disc jockeys were fired after playing an audiotape of the beheading of American Nick Berg by Iraqi militants and cracking jokes about the grisly death.
Listeners called the radio station to complain after hearing Berg's bloodcurdling screams in the broadcast of the tape, followed by the DJs laughing and playing musical accompaniments.
The DJs, known as Marconi and Tiny, were fired Thursday from their morning show perch at Portland's KNRK-FM, which is owned by Pennsylvania-based Entercom Communications Corp. Station employees would not release the legal names of the DJs.
The station's manager sent an apology out over the airwaves, saying: "The actions of the KNRK news morning show were insensitive, inappropriate and repulsive. On behalf of Entercom Portland and KNRK, I apologize to our listeners."
One of the DJs apologized on his Web site, posting a statement that read, "I have become so numb to the horrific things that happen in this world that I sometimes forget there are still people who feel. I in no way meant to be insensitive to anyone. My comments on this were inapropriate [sic]."
Berg's headless body was found Saturday in Baghdad. Three days later, a videotape posted on an al-Qaida-related Web site showed him being decapitated
