In the first major fallout of the deadly bombing of United Nations Baghdad headquarters, two top officials of the world body, including its global security coordinator, were sent on leave as a four-member team began investigations to fix the responsibility for lack of precautions despite highly charged atmosphere in Iraq.

Though a UN spokesman maintained that they had sought to be relieved of their duties for the duration of investigations, diplomats and officials said that they had no other choice.

The investigation team, appointed by Secretary General Kofi Annan, is charged with determining 'accountability at all managerial levels at headquarters (in New York) and in field'.

Sent on leave till at least mid-January are Security Coordinator Tun Myat of Myanmar and acting head of the UN mission in Iraq Lopes da Silva of Portugal, who was responsible for security at the time of bombing.

The August 19 bombing of the Baghdad headquarters killed 22 people, including head of the mission Sergio Vieira de Mello who was with the mission for a short duration. Silva took over after de Mello was killed.

The bombing shook the United Nations into re-evaluating security of its operations across the world as Annan and his top advisers realised that UN flag does not automatically provide security to its staff.

The two officials stepped down as Annan ordered a 'strategic reorganisation' of security management under the leadership of Deputy Secretary General Louise Frechette.

Annan's actions to improve security comes in the wake of highly damaging report by an independent panel headed by former Finnish president Martti Ahtisaari who described the

UN security system as 'dysfunctional' and 'sloppy' and questioned judgment of the UN top officials in refusing offer of security from the United States-led coalition, the 'only credible' force in the country.

The report also sharply criticised the United Nations for not even keeping a record of how many of its people were in Baghdad and not taking simple measures as providing shatterproof glass.

Several people were injured by the flying glass.

The Ahtisaari panel had also faulted Frechette but the UN spokesman said Annan has 'full confidence' in her.

A spokesman, when asked specifically whether the two officials were forced to go on leave in the wake of media reports saying that they were virtually suspended, asserted that they had asked to be relieved of their duties.

"Accordingly, the Secretary General has decided that they will take special leave until mid January while remaining available to the team to provide any relevant information," he said.

To a question whether they had no other choice, he repeated the same answer.

UN Under Secretary General for Management Catherine Bertini, an American, would look after security temporarily.

The four-member investigation team is headed by former high commissioner for refugees Gerald Walzer and includes a former UN legal official Srinath Basnayake, Assistant

Commissioner of Irish National Police Kevin Carty and senior security manager for high commissioner for human rights in Geneva Stuart Groves.

PTI