Police in South Africa have used force against supporters of the head of the governing ANC's youth wing.
The demonstrators were trying to get close to the ANC headquarters in Johannesburg where their leader Julius Malema is attending a disciplinary hearing.
The BBC reports Mr Malema, 30, is accused of ''sowing divisions'' in the party and bringing it into disrepute by calling for Botswana's government to be overthrown.
Once a close ally of President Jacob Zuma, Mr Malema is now a fierce critic.
If found guilty by the hearing, Mr Malema could be suspended from the party for several years.
It is his second disciplinary hearing in just over a year.
His supporters threw stones at police who were blocking them in Johannesburg on Tuesday.
The police erected a steel gate and barbed wire to close the main street leading to Luthuli House, the African National Congress headquarters where the hearing was held.
Thousands of Mr Malema's supporters remained outside for much of the day, chanting and setting rubbish on fire.