JOHANNESBURG, South Africa (AFP) -- President Cyril Ramaphosa on Tuesday urged South Africans not to blame migrants for the country's problems, after a recent wave of anti-immigrant unrest and violence. One of Africa's largest economies, South Africa has long attracted migrant workers from across the continent, both legally and illegally. But in recent weeks, mobs of South Africans carrying sticks, whips and shields have marched through parts of the country...