Hostage murdered on tape

Iraq's hostage crisis has descended into new horror after an Italian kidnap victim was killed by his captors.

The private security guard's murder was filmed by the extremist group which had taken him and three other Italians.

The killing immediately raised fears over the fate of other kidnap victims in Iraq as a wave of hostage-taking sweeps the country.

Fabrizio Quattrocchi was last seen alive on a videotape sent to Arabic broadcaster Al-Jazeera in which his previously unknown kidnappers, the Green Brigade of the Prophet, demanded the withdrawal of Italy's 2,500 troops from Iraq, promising to kill the men if their ultimatum was not met.

Their threat was carried out after Italian prime minister Silvio Berlusconi refused to order a withdrawal, a spokesman for Al-Jazeera said. "They slaughtered the hostage because of Berlusconi's remarks refusing to withdraw troops from Iraq," the spokesman said.

He said the station had a tape of the killing but added: "We won't air it because it is too bloody."

The 35-year-old hostage's death came despite the intervention of Iran, which had sent a delegation to Baghdad to try to negotiate the release of the four men.

Iran's failure to stop the militants will only increase fears that Iraq's security situation is out of control, as until now it had been seen as certain to wield influence over Shi'ite groups.

The killing came as Moqtada al-Sadr, the Shia cleric wanted "dead or alive" by the Americans, renewed his offer of " unconditional" talks with US forces.

But there was a warning today from America's most senior military officer that al-Sadr's capture would not calm the country.

Air Force General Dick Myers, chairman of the joint chiefs of staff, spoke as he toured Baghdad to warn that there would be an upsurge in violence if al-Sadr was taken into custody. "It may well be that if he is captured, violence could increase for a bit," he said.

The general also made a pointed visit to Italian troops as a gesture of support after the capture of the four hostages and the murder.

Mr Berlusconi has now promised not to pull out troops, and has been backed by the main opposition leader Pietro Fassino.

Meanwhile it emerged today that Tony Blair is to despatch a heavyweight diplomat to Iraq in an attempt to boost British influence amid tensions with America.

The move came as the Prime Minister flew to crisis talks in the US and with his relationship with George Bush facing its toughest challenges yet.

A series of dangerous issues were threatening to cloud the talks, including disagreements over the US-led security clampdown and the role of the United Nations and disputes over intelligence failures before September 11.

The decision to send a new ambassador to Baghdad in July comes only days after Tory leader Michael Howard voiced concerns about the replacement of former envoy Sir Jeremy Greenstock with a more junior diplomat.

Sir Jeremy's replacement, his former deputy Paul Richmond, will hand over to the new ambassador after being in post for only a few weeks, although the Foreign Office insisted his posting had not been cut short. The move will be seen as evidence that Britain is concerned its voice is not being heard enough by US commanders on the ground.

Mr Blair is desperate to persuade the president to give the UN a bigger status when Iraq is handed over to local rule on 30 June. He will meet UN secretary general Kofi Annan in New York tonight.