Economic Freedom Fighters' members stormed into the Gauteng legislature during their march in Johannesburg on Tuesday.
The party members had marched to the legislature to protest against the removal of their MPLs during a sitting on July 1.
On arrival at the legislature, they pushed through a human chain of police officers in front of the building and stormed inside.
Other members who were prevented from getting in when the door was shut and locked continued to sing struggle songs in front of the legislature where police struggled to maintain order.
Those who got in were removed, except for the party's provincial leaders and its leader Julius Malema. They were in a meeting in the building around noon on Tuesday.