The United Nations has decided to hold an independent inquiry into the deadly bombing of its headquarters in Baghdad, conceding the demand of the staff members who had reservations about the internal investigation that it is already in progress.

The report of the internal inquiry is expected within a week or two but it is not clear whether it would be made public. No one has yet been named to hold independent inquiry.

There was no formal announcement but in an email sent to the employees Under Secretary-General for Management Catherine Bertini said, "An independent inquiry will be conducted to investigate our security arrangements in the run-up of the bombing."  

The independent inquiry is likely to settle the controversy whether the US-led coalition did not provide enough security or the United Nations rejected a US offer for security as it did not want to appear to be working out of a fortress and wanted to provide easy access to Iraqis.

The UN says it has not been able to confirm that on any occasion the world body refused an offer of security, but at the same time asserts that it does not want to live in an armed camp.

UN chief spokesman Fred Eckhard said the world body is reassessing security since 'we became vulnerable'. At the time of bomb explosion, the US was putting up a 12-foot concrete wall in response to an increased security threat 'that they perceived and we acknowledged'.

The Security Committee of the Staff Union had been agitating for an independent inquiry to determine why adequate security was not available at the Baghdad headquarters.

It is also demanding to know why so many staff members were in the headquarters when it was a high security area where only essential staff should be allowed.

Eckhard said more international staff would be withdrawn from Iraq but the UN would ensure that there is only minimum disruption.

The strength of the staff has already come down to 400, including 110 in Baghdad.

Officials say it is planned to withdraw another 50 from Baghdad and around 150 out of some 300 in northern Iraq. Most of the work would be carried out by local staff.

Eckhard admitted the UN cannot carry on work as efficiently as it does with only half of the international staff inside the country.