JOHANNESBURG (CBSNewYork) — Former President Barack Obama issued a warning Tuesday about what he says is a growing number of politicians who push “politics of fear, resentment and retrenchment.”

Obama spoke in South Africa at an event marking what would have been the 100th birthday of the late Nelson Mandela.

The former president also spoke about the importance of equality and human rights and other values he says are under threat.

About 14,000 people gathered to hear the speech at a cricket stadium in Johannesburg.