The South African government says an ambulance carrying Nelson Mandela to a hospital two weeks ago had engine trouble and the former leader was then transferred to another ambulance for the rest of the journey. It said care was taken to ensure the condition of the 94-year-old was not affected.

The office of President Jacob Zuma said in a statement Saturday that it was confirming media reports about the transport problem at the time of the former leader's hospitalization. Zuma's office says doctors believe Mandela suffered "no harm" during that period.

The statement also says that Mandela remains in a serious but stable condition in a hospital. The government has previously said that the anti-apartheid leader and Nobel Peace Prize laureate was being treated for a recurring lung infection.