The medical relief NGO immediately announced that it would cut its contingent of seven expatriates. While 45 Iraqi staff will remain, the charity cannot guarantee that its work in the slum area of Sadr City will go on.
"For many months, the climate of violence in Iraq has already made it very difficult for international humanitarian organisations to provide meaningful assistance," an MSF spokeswoman said. "It is hard to gauge what the effects of this attack will be on the future of humanitarian assistance in Iraq. MSF will scale down its current expatriate team of seven in Baghdad, who have set up clinics and support a hospital in the poorest part of the city, but hopes to continue its medical activities as much as is possible."
The International Committee of the Red Cross, the target of a suicide bomb attack in which 14 Iraqis, including two Red Cross workers, were killed, said it would decide within days whether to pull out staff in response to the bombing. But some further diminution of its presence seems likely.
A spokeswoman in Baghdad said: "Without a doubt, what happened here today will affect any decision on our future role."
Since July, the Red Cross has withdrawn 80 international staff, in response to attacks on its staff and the bombing of the UN compound in August.
Now just 50 staff remain, supporting several hundred local workers.
Nicholas Young, chief executive of the British Red Cross, said the charity remained committed to helping the Iraqi people through the provision of safe drinking water, visiting detainees and reuniting separated families.
Care International, the only UK-based NGO operating in Baghdad prior to the war, was meeting to determine its response to the bombings as Third Sector went to press. It has eight expatriate staff in the Iraqi capital.
But medical relief charity Merlin said it had no plans to cease operations in Baghdad. Its three expatriate staff have told been to stay at home while an evaluation is made of the security situation.
Other agencies have already withdrawn from Baghdad. Save the Children pulled out its international staff, leaving just two people behind to monitor developments. Oxfam evacuated staff members to Jordan following the attack on the UN compound in August.
Jonathan Potter, chief executive of People in Aid, which promotes good practice in the treatment of aid workers, said: "All agencies should have security plans, risk assessments and evacuation procedures. But they are on the ground and they will know if the evacuation trigger has been reached."