Johannesburg - Economic Freedom Fighters leader Julius Malema urged marchers to take their time on Tuesday as they made their way to the SABC's Auckland Park offices in Johannesburg.
"This thing of us pushing each other is not helping," he told marchers.
"We must not run, let us take our time and not push each other."
Thousands of EFF supporters led by Malema were marching to the public broadcaster to hand over a memorandum following the SABC's refusal to air the party's election commercial.
Five police cars led the march with a sea of red berets behind.
Placards were hoisted high in the air as supporters sang and danced.
Marshalls struggled to contain marchers. Both sides of Empire Road were occupied by marchers, causing a traffic jam.
The march is in protest against the public broadcaster refusing to air the party's election commercial.
The SABC claims the advert, which includes the slogan "destroy e-tolls physically", incites violence.
The Independent Communications Authority of SA agreed with the SABC in a special hearing.
Traffic was heavily affected as cars were turned back or re-routed at every intersection the marchers approached.
One frustrated motorist tried to drive through the crowd but met a wall of red beret-wearing marchers.
The car was turned away and escorted out of the crowd by marshals and police. Download the app by visiting one of these app stores.