workingclasshistory:

On this day, 13 December 1971, 6,000 indigenous Ovambo workers in what is now Namibia went on strike and began a boycott of food from work kitchens against an exploitative apartheid forced contract work system.
The government called in white students and non-Ovambo Black workers as scabs and sent police to attack the strikers, but the stoppage spread. By 3 January many workplaces and every major mine was on strike.
The South African government then agreed to reform the contract system, but the strike continued until January 21 when they officially abolished the system and granted massive concessions, including freedom for workers to choose or leave jobs and free medical care.
This is a short history of the dispute: https://libcom.org/history/ovambo-migrant-workers-general-strike-rights-namibia-1971-72 https://www.facebook.com/workingclasshistory/photos/a.296224173896073/1291935820991565/?type=3