sentences:  Thatcher's opposition to economic sanctions was challenged by visiting anti-apartheid activists, including South African bishop Desmond Tutu, whom she met in London, and Oliver Tambo, exiled leader of the outlawed ANC guerrilla movement, whose links to the Soviet bloc she viewed with suspicion, and whom she declined to see because he espoused violence and refused to condemn guerrilla attacks and mob killings of black policemen, local officials and their families.At a Commonwealth summit in Nassau in October 1985, Thatcher agreed to impose limited sanctions and to set up a contact group to promote a dialogue with Pretoria, after she was warned by Third World leaders, including Indian Prime Minister Rajiv Gandhi and Malaysian Prime Minister Mahathir Mohamad, that her opposition threatened to break up the 49-nation Commonwealth.In return, calls for a total embargo were abandoned, and the existing restrictions adopted by member states against South Africa were lifted.