Cape Town — The former Nigerian president, Olusegun Obasanjo, has told African leaders who outstay their people's welcome that "time is running out" for them.

Speaking at the launch of the Africa Progress Panel's 2011 report at the World Economic Forum on Africa, Obasanjo suggested that such leaders "are really becoming extinct... how many of them do we have left today?"

But he urged those who remain to be reassured that "there's life after the State House." However, he said some lived in "fear of the unknown" and urged that after retirement -- unless they had committed "heinous crimes"-- they should be given "something they can do usefully" for their countries or for the continent.

At the same news conference, former United Nations Secretary-General Kofi Annan defended the International Criminal Court against criticism that it targets only African leaders.

"The ICC is not after Africa," he said. "Most complaints [about the ICC] are not from victims... often we say this in protection and in defence of the accused... [But] don't the victims of today... and potential victims of tomorrow need protection?"

He said most prosecutions against Africans had been initiated when governments were unable or unwilling to bring charges themselves. If Africa developed its judicial systems, cases would not need to be referred to the ICC.

"If the leaders stay ahead of the curve, reform or move on when their terms are up, and not try to hang on... we should be okay," he said.