A statement from the South African government called the US withdrawal "unnecessary" and said the conference would continue.

Mr Powell had already boycotted the event, but a mid-level US diplomatic team had been sent to Durban where it was heavily involved in behind-the-scenes efforts to amend the wording - although they took no public role in the conference.

Israeli Foreign Minister Shimon Peres called the activities at the South African conference an "unbelievable attempt to smear Israel."

"An important convention that's supposed to defend human rights became a source of hatred," he told a news conference in Jerusalem.

'Racist crimes'

On Sunday, a human rights forum coinciding with the conference equated Zionism - the movement which led to the establishment of a Jewish state in 1948 - with racism and called for international sanctions against Israel.

Israeli delegate Mordechai Yedid made a strongly-worded speech to the conference on Monday saying Arab and Islamic states trying to label Israel and Zionism as racist were being anti-Semitic themselves.

Amr Moussa - the former Egyptian foreign minister who now heads the League of Arab States - warned against the issuing of a final declaration in which too much weight was given to one side.

"What is the use of the document that will be tilted to one or the other. It will just be condemned and thrown away and not implemented at all," he said.

Divided on slavery

Divisions have also emerged among European countries on whether to apologise for the slave trade between Africa and the New World, with former slave traders Britain, Spain, Portugal and the Netherlands holding out against pressure to apologise and agree it was a crime against humanity.

Other countries that were not, led by current EU president Belgium, want to move closer to African and black American demands for an apology.

A senior African-American campaigner, the Reverend Jesse Jackson, said a failure to apologise would indicate that these countries were proud of their colonial past.

"If you don't feel apologetic for slavery, if you don't feel apologetic for colonialism, if you feel proud of it, then say that," he told the BBC.

"But if one has a sincere desire to overcome the ravages of the past it doesn't take much to apologise and move towards some plan for restoration."

Some countries may indeed fear that an apology would add momentum to demands that those which traded in slaves pay reparations.