Stars including Josh Groban and Pharrell Williams ‏have reached out to Nelson Mandela following the news the former South African leader has been placed on life support in hospital.

The humanitarian icon was hospitalised in Pretoria on 8 June (13) for a recurring lung infection, but his condition took a turn for the worse last week (ends23Jun13), and on Wednesday (26Jun13) officials revealed his health had deteriorated further.

Groban took to his Twitter.com page after the announcement to tell fans, "Keep Mandela, and the great lessons of peace and tolerance he taught the world, in your thoughts as he fights to stay strong", while rapper Raekwon adds, "Prayers goes out to Nelson Mandela!"

And Williams writes, "Sending love and prayers out to Mandela and his family."

Fans of Mandela had been given a boost earlier on Wednesday when it was revealed the former leader had opened his eyes for the first time in days after learning of a planned visit from U.S. President Barack Obama on Friday (28Jun13).