Nelson Mandela, the former president of South Africa, was in "serious but stable condition" today after contracting a lung infection, South Africa officials said.
The 94-year-old Nobel Peace prize winner's "condition deteriorated and he was transferred to a Pretoria hospital," early this morning, according to statement from the office of South African President Jacob Zuma.
"The former President is receiving expert medical care and doctors are doing everything possible to make him better and comfortable," the statement said. "President Jacob Zuma, on behalf of government and the nation, wishes Madiba [Mandela's clan nickname] a speedy recovery and requests the media and the public to respect the privacy of Madiba and his family."
PHOTOS: Nelson Mandela Through the Years
In April, Mandela spent 18 days in the hospital due to a lung infection and was treated for gall stones in December 2012.
Mandela served as the first black president of South Africa from 1994 to 1999.
In 1993, he received a Nobel Peace Prize for his work in ending apartheid through non-violent means.
ABC News' Gillian Mohney contributed to this report.