The UN is considering the future of its aid program in the country, while most staff in Baghdad are not expected to return to work for at least the next 24 hours.
After last month’s car bombing, which killed more than 20 people, the UN had already cut its foreign staff in Baghdad from about 300 to just 100.
Aid workers say they do not want to be cut off from Iraqi people behind barricades and barbed wire, but that their lives must also be protected.
UN spokeswoman in Iraq, Antonia Paradela, says the latest bomb attack makes it even more difficult for aid workers to do their job properly.
She said: “The UN is asking itself right now, can the UN work in Iraq the way it needs to – being open, going out, working with other Iraqis.”
US President George W Bush, who addresses the UN General Assembly on Tuesday, said it would be helpful to get UN help in writing a constitution for Iraq or in overseeing an election.
And French President Jacques Chirac has said France will not veto a US-backed Security Council resolution on the future of Iraq.
France, with Germany, had been demanding an early transfer of power from the Coalition Provisional Authority to Iraqi representatives.
But US national security advisor Condoleezza Rice says a French demand that Iraqis regain sovereignty over their country within months “isn’t workable.”
She said a constitution and democratic elections have to occur in Iraq before sovereignty can be returned to the Iraqi people.
The US is seeking a new resolution at the UN Security Council seeking international reinforcements for a multi-national force in Iraq and funds to help the reconstruction of the country.