A previously unknown Iraqi group has claimed responsibility for the attack on the U.N. headquarters in Baghdad this week. The Arabic television channel, Al-Arabiya, received a statement on Thursday from the group, warning Arab countries against sending forces to Iraq.

An airplane has left Brazil for Baghdad to recover the body of the top U.N. envoy, Sergio Vieira de Mello. De Mello was killed by the Tuesday bombing in the Iraqi capital.

Al-Arabiya said it received the statement on Thursday but did not say how or where it received it. The statement warned Arab countries against sending armed forces to Iraq and called for continuing what it called acts of holy war against all those who help the Americans.

Numerous groups have sent written and taped statements to Arabic television channels claiming responsibility for the almost daily attacks on U.S. troops, but most of them have never been heard of again.

US military officials say it's difficult to determine whether any of the groups exist beyond their videotapes and written statements and are responsible for the attacks.

The United Nations has announced that it's pulling about a third of its staff out of Iraq following the deadly bomb attack on its Baghdad headquarters.

UN support and administrative staff, numbering about 100 out of a total workforce of 300, are being flown to Jordan and Cyprus, according to a UN official.

"We were about 300 in Baghdad on Tuesday, we will be about 200 in Baghdad as of Saturday onwards and we have colleagues coming in as we speak - arriving now - to start that process of rotating staff. The Secretary-General said this would not deter the UN and we intend to continue as we were doing," said Romiro Lopez Da Silva, Iraq coordinator for UN humanitarian programmes.

On Thursday, three more bodies were pulled from the rubble of the UN headquarters, raising the death toll from the truck bomb to at least 23. Two UN staffers are still unaccounted for.

(CCTV.com August 22, 2003)