Pictures circulating on social media in Tanzania show President John Magufuli visiting the former first lady, Maria Nyerere, in hospital.
Last week, there were reports that Mrs Nyerere, widow of the country’s founding President Julius Nyerere, was unwell and had to return to Tanzania from Uganda, where she had gone for a pilgrimage.
Details of her illness have not been released.
The pictures appear to show Mrs Nyerere, 88, eating her breakfast. The president and his wife, Janet Magufuli, are also seen praying next to the former first lady. BBC News