Up to 15 people have been killed and dozens injured in a bomb attack on the United Nations headquarters in the Iraqi capital, Baghdad.
Eyewitnesses said a suicide bomber in a cement truck ploughed through security barriers and into the headquarters.
The UN says its Special Representative in Iraq, Sergio Vieira de Mello, is among the dead. Vieira de Mello, a Brazilian, had been trapped under the rubble.
US President George W Bush denounced those behind the attack and vowed that that the US-led reconstruction efforts would continue.
UN Secretary General Kofi Annan condemned the bombing as an act of unprovoked and murderous violence. He is cutting short a holiday in Northern Europe to return to New York.
Former Iraqi Vice President captured
Earlier, former Iraqi Vice President Taha Yassin Ramadan was captured in the northern city of Mosul and turned over to US forces. A senior official of the Patriotic Union of Kurdistan (PUK) said their fighters caught the former second-in-command to Saddam Hussein.
Further south, US Army engineers having been dropping water from helicopters to try to douse the flames on the main Iraqi oil export pipeline to Turkey. The pipeline reopened last Wednesday but was shut down two days later after saboteurs set it alight.
The US installed administrator, Paul Bremer, said hardcore supporters of Saddam Hussein are behind the latest wave of sabotage attacks. He said that as well as targeting the oil export pipeline, saboteurs had been mounting frequent attacks on the power grid.
Sabotage and theft of power cables have caused repeated electricity blackouts in the south of Iraq and badly hit exports from the country's southern oilfields.
