EXPLAINER: What caused South Africa's week of rioting?

South Africa has been rocked by the worst violence since the nation achieved democracy in 1994

JOHANNESBURG -- South Africa has been rocked by the worst violence since the nation achieved democracy in 1994. Here is a closer look at the unrest. WHAT TRIGGERED THE VIOLENCE? The unrest began on July 8 when former President Jacob Zuma started serving a 15-month prison sentence for contempt of court. Supporters in his home province of KwaZulu-Natal set up roadblocks on major highways and burned about 20 trucks. The protests closed the N3 and N2 highways, which link the Indian Ocean ports of Durban and Richard's Bay to the industrial hub of Johannesburg and to Cape Town. The unrest spread within KwaZulu-Natal, where shopping malls and centers were ransacked by mobs that took food, electronics, clothes and liquor. Attacks on retail centers also spread inland to Gauteng province, to Johannesburg, the country’s largest city, and to Pretoria, the capital. In Durban and Pietermaritzburg, crowds attacked warehouses for major retailers and factories, which were set alight. Several burned until their roofs collapsed. The unrest lasted for a week until 25,000 army troops were deployed.