Mr Jonathan was widely praised for accepting defeat rather than plunging Nigeria into a crisis by challenging the election result.
But he said some of his allies were not impressed.
"So, for ministers and aides who served with me, I sympathise with them.
But he said some of his allies were not impressed.
"So, for ministers and aides who served with me, I sympathise with them.
They will be persecuted. And they must be ready for that persecution," Mr Jonathan added.
During the election campaign, Gen Buhari pledged to tackle corruption in Nigeria, Africa's main oil producer.
The BBC's Muhammad Kabir Muhammad in the capital, Abuja, says many people want him to live up to the promise by investigating numerous corruption scandals that hit Mr Jonathan's government Read More.
