Slaughter of yet another hostage follows a grisly pattern that is becoming routine

The news of Eugene Armstrong's savage murder emerged in what has become a fixed pattern.

The news of Eugene Armstrong's savage murder emerged in what has become a fixed pattern.

Firstly the Associated Press news agency and others reported that a posting on an Islamist website claimed an American hostage had been "slaughtered" and that the group claiming responsibility would soon provide video proof.

Shortly afterwards the bloody evidence was provided. On the same website used to announce the killing, the group posted a nine-minute video which showed a masked man cutting off the head of the hostage, who screamed as his throat was cut. The man's head was then held aloft before being placed on his body. One of the five kidnappers promised that two other hostages being held - one of them a Briton - would also be killed unless the US released all women prisoners it was holding.

The group claiming responsibility for the killing identified itself as Tawhid and Jihad, an organisation led by Abu Musab al-Zarqawi, who is said by the US to have links to al-Qa'ida. The same group also claimed responsibility earlier this year for the kidnapping and beheading of another American, the businessman Nicholas Berg. He too was beheaded while dressed in the sort of orange jumpsuit used in US prisons.

There have been numerous beheadings of hostages in Iraq. At the weekend a video posted on another Islamist website showed the beheading of three Kurdish political workers whose decapitated bodies were found last week. Before that, 12 Nepali contractors were killed by their kidnappers and some were beheaded. In all of these cases - as with the beheading of the American Paul Johnson earlier this summer in Saudi Arabia - news of the killings has emerged in a similar fashion with proof being provided by means of video footage. The prevalence of the internet and the digital technology means that these deaths are, in effect, carried out in public.

"These people are scum," said Tucker Eskew, an adviser to President George Bush's reelection campaign, as news of the beheading emerged yesterday evening. "This shows the extent to which they will stoop."

From the perspective of the Bush administration, this latest killing could not have come at a worse time. With Iraq's interim Prime Minister, Iyad Allawi, due to visit Washington later this week, Mr Bush and his senior advisers have been arguing that progress is being made, that the security situation is improving and that the planned elections are still due to take place in January. Instead, Mr Armstrong's beheading has provided Mr Bush's critics with more evidence that the situation in Iraq remains deadly and chaotic.

Mr Bush, speaking in New Hampshire before the video was released, said: "We will stay on the offensive against them. They will behead people in order to shake our will. These people are ideologues of hatred."

The execution of Mr Armstrong has also focused attention once again on Zarqawi, the Jordanian-born extremist who has been blamed by Washington for organising and planning much of the anti-American resistance and violence in Iraq.

The US has offered $25m (£14m) for information leading to the capture or killing of Zarqawi, whose real name is Ahmad Fadhil al-Khalayleh and who is said to be trying to build a network of foreign militants in Iraq to work for al-Qa'ida.

In May, when Mr Berg was murdered, some reports suggested that it was Zarqawi who personally carried out the beheading. In June his network was also blamed for the murder of a South Korean contractor, Kim Sun Il, who was also beheaded after being taken hostage.

Yesterday it was reported that the kidnapper, whose voice is heard on the videotape threatening to kill the two other hostages unless the group's demands are met, sounded like previous recordings attributed to Zarqawi. Earlier this year his group released what was, in effect, a promotional video showing its suicide-bomb attacks on police stations and other targets in Iraq.