Former South African president Nelson Mandela was admitted to a Johannesburg hospital Wednesday for what his foundation described as "routine tests."

Mandela was admitted to Milpark Hospital Wednesday afternoon, Sello Hatang, spokesperson for the Nelson Mandela Foundation, said in a statement. "He is in no danger and is in good spirits," the statement read.

Journalists who camped outside the hospital reported seeing several of Mandela's family members arriving throughout the day.

Mandela became South Africa's first black president in 1994. He spent 27 years in prison after he was convicted of plotting against the apartheid government, and was released in 1990. He served one term as president, stepping down in 1999.

After leaving public office, Mandela became a seemingly tireless humanitarian, starting a number of foundations in his name and speaking out about social justice issues.

His health has deteriorated in recent years, and he has not been seen in public since the closing ceremonies of last year's World Cup.

Earlier this month, a report falsely claiming Mandela had died circulated on social networking site Twitter. The African National Congress called the report malicious and insensitive.