Mandela urges Nigeria boycott

South African president Nelson Mandela yesterday called for the United States, Britain and China to back an international oil boycott of Nigeria for its execution of Ken Saro-Wiwa and eight other human rights activists. African countries acting alone lacked the economic muscle to ''bring [General Sani] Abacha to his knees'' and force a return to democracy in the country, Mr Mandela said.

Meanwhile in Britain, around 100 Shell petrol stations were picketed by members of Greenpeace and Friends of the Earth.