Nelson Mandela back in hospital

JOHANNESBURG, South Africa — Nelson Mandela is responding well to hospital treatment for a lung infection, the South African government says.

South Africa's 94-year-old former president was admitted to an undisclosed facility late on Wednesday night, according to President Jacob Zuma's office.

Mandela remains "conscious," said presidential spokesman Mac Maharaj, but he has told the public little more. He said the government will give doctors space to do their work, and will not be releasing further information unless Mandela's health takes a turn for the better or worse.

President Zuma, in an interview with BBC News, said the country "must not panic."

"He's responding very well [to treatment]. And he's in good hands, very good doctors. And I think all of that brings comfort to all of us," Zuma said.

President Barack Obama said "we're all deeply concerned" and that he hopes Mandela will soon recover.

"He is a hero, I think, to all of us," Obama told reporters. "We will be keeping him in our thoughts and prayers, and his entire family."

As Obama noted, South Africa's first black president has beaten previous health scares.

Earlier this month, Mandela spent a night in the hospital for what was described as scheduled medical tests. But a recurrence of a lung infection is a potentially far more serious situation given the anti-apartheid icon's age and fragile health.

Mandela has been hospitalized twice in the past few years for lung infections, including for nearly three weeks in December during a stay that also included a surgical procedure to remove gallstones.

Maharaj is refusing to say which hospital is treating the man South Africans call "Madiba," citing reasons of privacy. But he is likely at either the private hospital in Pretoria, where he stayed in December, or at the heavily secured One Military hospital, also in Pretoria.

Mandela has suffered respiratory problems ever since his time in jail on Robben Island, when he worked in a limestone quarry and contracted tuberculosis. He spent 27 years in prison until his release in 1990. Four years later, he became South Africa's first black president.

The aging icon is increasingly frail and very rarely seen in public. Any changes in his health are closely watched in South Africa and beyond.

"We appeal to the people of South Africa and the world to pray for our beloved Madiba and his family and to keep them in their thoughts," President Jacob Zuma said. "We have full confidence in the medical team and know that they will do everything possible to ensure recovery."

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Senior Correspondent Erin Conway-Smith reported from South Africa. Follow her on Twitter @ejcs.