It was not immediately clear what the protesters were demanding, but the unrest began in the early hours of the morning. Residents went on to barricade major roads leading out of Soweto with burning tyres and rocks.
Metrorail Gauteng spokesperson, Lillian Mofokeng, said at least 20 trains were cancelled between New Canada and Mzimhlophe.
"Trains running between New Canada, Orlando and Midway corridor are not affected," Mofokeng said. "Commuters are advised to seek alternative transport this morning to get to work or school."
Mofokeng said Metrorail was committed to ensure safety of commuters, staff and assets and therefore would continue to closely monitor the situation before resuming services.
"Metrorail would like to apologise to commuters and employers for the inconvenience this might cause and assures them that their safety remains our number one priority."