South African police fired rubber bullets to repel hundreds of rock-throwing farm workers during a strike for higher wages on Thursday, during a second day of violence in the normally calm and picturesque wine lands.

Police and farmworkers fought running battles along the N1 motorway which links Cape Town and Johannesburg, halting traffic and shutting off a number of towns and villages.

Protesters near De Doorns set barricades on fire and threw rocks, stones and debris at police vehicles, prompting officers in riot gear to respond with a volley of rubber bullets and tear gas.

Protesters were dispersed but rapidly re-gathered, in a game of cat and mouse that has rocked Africa's main wine producing region.

Farm workers in the Western Cape on Wednesday launched a fresh round of industrial action to press for the doubling of their wages.

Thousands of labourers have downed tools after wage negotiations collapsed following last month's work stoppage that left two people dead.

Workers who pick and pack fruit on farms in the picturesque region are demanding a wage hike from 69 rand ($8) to 150 rand ($17.50) a day.

The latest bout of industrial action follows unprecedented work stoppages in the country's key mining industry that turned violent late last year leaving more than 50 people dead.

Of those killed, 34 were shot dead by police in one day in scenes reminiscent of apartheid police brutality.