International outrage and violent demonstrations in the centre of Johannesburg followed the execution yesterday in Pretoria of Benjamin Moloise, a black South African poet. The execution - carried out in spite of pleas from around the world for clemency - prompted an angry response from Commonwealth heads of government, meeting in Nassau. Efforts are under way there to draw up a joint policy aimed to end apartheid in South Africa. [Article continues to describe Margaret Thatcher's involvement, and the meeting of the Commonwealth leaders/how they plan to work to end apartheid.]