South Africa’s president says the turmoil in his country’s mining industry has cost more than half a billion dollars in lost gold and platinum production.

Jacob Zuma was speaking to the Congress of South African Trade Unions, an alliance party of the governing African National Congress.

However, it is the credibility of the federation that has been questioned after violence during the mining protests.

Al Jazeera's Mike Hanna reports from Midrand in Johannesburg.