British hostage Mr Kenneth Bigley, facing a death threat from Iraqi kidnappers, appealed to British Prime Minister Mr Blair for his life in a videotape released on Islamist Web sites tonight.
"I need you to help me now Mr Blair, because you are the only person on God's earth who can help me," he said in the video, apparently made by the Tawhid and Jihad Group of al Qaeda ally Abu Musab al-Zarqawi, which is holding him hostage.
Earlier Iraqi judges ordered the conditional release of three prisoners in US custody, including one of two women held by US forces, the country's national security adviser has said.
Mr Kassim Daoud told a news conference that the release would be conditional and would not happen for a few days.
But the US embassy said earlier that neither of the two women in US custody would be released imminently.
Militants who have killed two US hostages say they wil behead Mr Bigley unless Iraqi women are freed from US prisons.
Mr Bigley's two work colleagues were beheaded, probably both by the same man - al-Qaeda ally Abu Musab al-Zarqawi.
The message on the Islamic Web site which announced the beheading of the second US hostage threatened that Mr Bigley would also die if the British government did not act.
"The British prisoner will meet the same fate if the British government does not carry out what it should do for his release," it said, adding that President George Bush would die in "rage" and Prime Minister Tony Blair would "cry blood."
A spokesman for the family of US hostage Mr Jack Hensley said the family has received confirmation that the body handed over to US officials in Iraq today is his. The family was told the news today, the day Mr Hensley would have celebrated his 49th birthday.
His decapitated body had been found along with the head in a black plastic bag on Tuesday night in Baghdad.
A Canadian woman who was kidnapped in Iraq two weeks ago has been freed and is in the hands of US troops, the Canadian Foreign Minister confirmed today..
"We were aware that she had been kidnapped and we had been working on the case. We're very relieved with this happy resolution," he told CTV television after it emerged that 38-year-old Fairuz Yamulky was safe.
She had not been previously reported as missing.
In the latest in a wave of car bomb attacks in the Iraqi capital, a suicide bomber detonated his vehicle in a crowded commercial street as dozens of men wanting to join the country's security forces queued up to photocopy their documents. Would-be recruits have been repeatedly targeted by insurgents.
Officials at Baghdad's Yarmuk hospital said 11 people were killed. At the scene, scores of sandals and shoes lay in pools of blood on the pavement. Iraqis covered burnt flesh lying on the ground with store banners torn down by the explosion. A nearby ice cream stall was destroyed in the blast.
Dazed survivors were shocked the area was targeted.
"They just bombed people eating ice cream," said Humam Abdul-Hadi, owner of a nearby shop. Shrapnel wounds peppered his face and neck and his T-shirt was stained with blood.