Former South African President Nelson Mandela is spending a second night in a hospital under medical supervision¹, amid growing concerns over his health.

南非前总统纳尔逊·曼德拉已遵医嘱在医院度过两个夜晚，其健康状况令人越来越担忧。

The president's office said Mr Mandela, aged² 92, was undergoing "specialised" tests in Johannesburg and "there is no need to panic".

Friends and family visited Mr Mandela during the day.

Security was tight outside the hospital and police were called to control traffic as a scrum（扭打，混乱） of journalists grew.

Media have also gathered outside Mr Mandela's home in Houghton, a wealthy suburb of north-east Johannesburg.

In a statement on Thursday, the South African presidency³ said it wanted to "assure the nation and the world that the former president is in high spirit".

"Dr Mandela suffers from ailment⁴（小病，不安） common to people of his age, and conditions that have developed over years. We may recall that he has suffered from tuberculosis⁵（肺结核） whilst on Robben Island and has had previous respiratory（呼吸的） infections."

President Jacob Zuma earlier said that Mr Mandela had flown from Cape⁶ Town to Johannesburg and had gone to the Milpark Hospital on Wednesday for a check-up.

Mr Zuma, speaking from Davos in Switzerland, where he has been attending the World Economic Forum⁷, said: "Given his age he has been taken into a hospital for a check-up. I'm sure check-ups are more frequent than when he was a healthy young man."

Children at a local school have hung messages of support outside the Milpark Hospital.

Word has quickly spread that Mr Mandela is in hospital, with US President Barack Obama adding his voice and wishes for a speedy recovery.