JOHANNESBURG — The South African government says former leader Nelson Mandela remains in critical but stable condition in hospital, though "medical interventions" are required because his health sometimes becomes unstable.

The office of South African President Jacob Zuma said Saturday that doctors are working hard for a "turnaround" in the condition of 95-year-old Mandela, who was admitted to a hospital on June 8 with what officials said was a recurring lung infection.

In a statement, Zuma's office quotes doctors as saying the former president and anti-apartheid leader has shown resilience and that his condition has tended to stabilize after medical treatments when his health deteriorates.

Zuma is urging South Africa to pray for Mandela and to keep him in their thoughts at all times.