Nelson Mandela said Wednesday there had been a tragic failure of leadership in Zimbabwe in his first public comments about the country’s political crisis.

In carefully worded comments at London dinner, Mandela said: “We watch with sadness the continuing tragedy in Darfur. Nearer to home we had seen the outbreak of violence against fellow Africans in our own country and the tragic failure of leadership in our neighboring Zimbabwe.”

While he did not name longtime Zimbabwe President Robert Mugabe, the comments come as Friday’s runoff presidential election has fallen into turmoil with the main opposition candidate withdrawing because of violence.

“The world remains beset by so much human suffering, poverty and deprivation ... It is now in the hands of your generations to help rid the world of such suffering,” Mandela said.

The dinner, attended by Prime Minister Gordon Brown and former President Bill Clinton along with celebrities including Oprah Winfrey, Denzel Washington and Robert DeNiro, is part of Mandela’s 90th birthday celebration visit to raise money for his AIDS charity.

Mandela’s comments were noteworthy not just because of his stature as a world leader, but because South African president Thabo Mbeki, who replaced Mandela, has steered clear of criticizing Mugabe. Mugabe was a staunch supporter of South African activists in their fight for independence.

For Mugabe, Mandela’s comments are a rebuke from a leader he sees as a fellow freedom fighter. They will be hard to dismiss or ridicule _ so often Mugabe’s response to criticism.

The head of South Africa’s African National Congress Jacob Zuma, however, came out against the Zimbabwe government this week saying the country is out of control.

Opposition leader Morgan Tsvangirai pulled out of the presidential run-off saying he could not ask his supporters to risk being killed for voting for him.

The withdrawal followed weeks of violence and intimidation blamed on Mugabe’s supporters. Mugabe’s Zanu PF party has said the presidential run off will go ahead as planned on Friday.

In Britain Wednesday, Queen Elizabeth II stripped Mugabe of his ceremonial knighthood to express Britain’s revulsion over human rights abuses.