The United Nations has ordered the withdrawal of its remaining international staff from Baghdad as part of a review of the security situation there.
The Red Cross has been in Baghdad for more than 20 years
"We have asked Baghdad staff to come out temporarily for consultations with people from headquarters on the future of our operation," UN spokeswoman Marie Heuze said in Geneva.
Even though the measure does not extend to northern Iraq - and UN officials insist they are not pulling out - the withdrawal effectively ends the presence of UN international staff in the Iraqi capital, says the BBC's Greg Barrow in New York.
The order comes amid ongoing attacks on aid workers - the latest was on the Red Cross headquarters in Baghdad on Monday, which killed 12 people including two ICRC guards.
The bombing was one of a series of co-ordinated attacks that left a total of 36 dead - making it the bloodiest day since the start of the US-led occupation.
Both the UN and the Red Cross have already said they will reduce their numbers in Iraq.
Fewer than 50 foreign UN workers are said to remain in Iraq after most were pulled out following a devastating attack on UN headquarters in August that also killed top UN envoy Sergio Vieira de Mello.
Saddam's right-hand man is said to be organising many of the attacks
US Defence Secretary Donald Rumsfeld said about 100,000 Iraqi security personnel were being deployed to aid the US-led troops.
But there were "no quick fixes" and aid agencies had to decide whether they wanted to stay in a country where "the attacker has the advantage".
"There's no doubt that terrorists are attempting to drive them out. And it appears that, at least with respect to some organisations, they're being successful," Mr Rumsfeld told reporters at the Pentagon.
In other developments:
- US troops carry out raids in Saddam Hussein's hometown of Tikrit, arresting a number of people
- A senior US defence official says Izzat Ibrahim al-Douri, who was officially number two in the former Iraqi regime, is helping direct the insurgency
- An explosive device sets fire to a goods train outside the flashpoint town of Falluja, 50 kilometres (30 miles) west of Baghdad
- Seven American companies which were awarded contracts worth $8bn to rebuild Iraq and Afghanistan donated more than $500,000 to President George W Bush's election campaign, Washington-based research group says
Local staff in charge
In a statement, Ms Heuze said the consultations would focus on the security arrangements that "we would need to take to operate in Iraq".
She said only the Baghdad-based staff would go - not UN workers in the northern city of Arbil, where the UN maintains a big presence.
UN operations in Baghdad will continue to be handled by Iraqi staff.
Last week, an independent report described security measures taken by the UN as "dysfunctional and sloppy".
It recommended a radical overhaul of the UN security system across the world.
The Red Cross has not yet determined how many staff to pull out - a move decided on in the wake of the first suicide attack ever on the humanitarian organisation.
The Red Cross has about 30 foreign workers in Iraq, plus about 600 Iraqi employees.