Well-wishers: children from the Rainbow-Hill Christian school sing outside the house of Nelson Mandela, on Tuesday. The former South African president, who is 94, has been in hospital being treated for a lung infection. The President of South Africa, Jacob Zuma, said on Tuesday that Mr Mandela's condition was "very serious", and that "all are praying" for his recovery. Archbishop Desmond Tutu has said that he is praying for Mr Mandela's "comfort and dignity".

The Archbishop of Cape Town, Dr Thabo Makgoba, published an open letter on Thursday. It called on Christians "to join with me in praying for God's tender merciful hand to be upon our former President, Nelson Mandela, at this time, and for his love to enfold dear Madiba, and all who are close to him."

It continued: "The Bible reassures us that 'God is our refuge and our strength, a very present help in trouble' (Psalm 46) and it is often when we feel most weak and vulnerable that God's reassurance comes to us most powerfully. It reminds us that in life, and in death, nothing can ever separate us from his love, and that his everlasting arms will never let us slip from his safe . . . grasp."