South Africa is mourning one of the leading lights of the anti-apartheid movement, Albertina Sisulu, who has died aged 92. Mrs Sisulu was the widow of Walter Sisulu, a friend and mentor of former South African President Nelson Mandela. A political figure in her own right, she was active in the women's league of the African National Congress (ANC). ANC spokesman Brian Sokutu said Mrs Sisulu had dedicated her life to bringing democracy to South Africa. 'She never gave up' Key figures from the governing ANC have been visiting Mrs Sisulu's family home in northern Johannesburg to pay their respects. Ahmed Kathrada, a lifelong friend and colleague, said he considered Mrs Sisulu a mother and was deeply shocked by the news of her passing. "Politically she was a great humanitarian, a great comrade, a loving comrade and an inspiration. She never ever gave up," South Africa's Eyewitness News quotes Mr Kathrada as saying. When news of her death broke late on Thursday evening, social networking websites in South Africa were flooded with tributes to the veteran campaigner, known affectionately as Ma Sisulu. Mrs Sisulu first met Walter Sisulu in the 1940s after she moved to Johannesburg to work as a nurse. Although not from a political background, she quickly established herself as an anti-apartheid activist in her own right and was among those who in 1956 led a march of 20,000 women protesting at being forced to carry passbooks. While her husband was confined to jail with Mr Mandela, she found herself subject to periods of house arrest. However, she also became an envoy for the ANC, visiting leaders overseas and drawing attention to the anti-apartheid struggle. In 1994 she took up her seat in South Africa's first democratically elected parliament. She was last seen in public in January this year, when she visited Mr Mandela during his stay in hospital. Source: BBC