The brawl took place in the presence of a large contingent of police personnel, traffic officers and members of the SA National Defence Force, who had lined the streets around the area to ensure there were no disruptions.

Zuma's supporters and those of the expelled ANC Youth League president confronted each other outside the hall, leading to the arrest of at least four Malema supporters for causing disruptions.

The four were driven off in a police van after their group started chanting slogans in support of Malema. Others carried placards reading "Bring back Malema", much to the chagrin of Zuma's supporters.

Inside the Christ Worship Church - where Zuma was to deliver the lecture - ANC Youth League Limpopo chairman Rudzani Ludere was assaulted by ANC members disapproving of his call for ANC leadership change.

This led to Ludere, his secretary, Jacob Lebogo, and the league's Peter Mokaba regional chairman, Jossey Buthane, staging a walkout with a handful of supporters in tow.

Earlier, Zuma's supporters used finger gestures to show they supported him in his bid for re-election as ANC president in Mangaung.

After the arrest of the four, the remaining Malema supporters moved away from the venue as those backing Zuma continued singing his praises.

Inside the hall, Zuma spoke about Mandela's heroism and how he mobilised people around the ANC's cause.

He said Mandela attracted people like a magnet through persuasion.

"His amicable manner, coupled with his exceptional organisational skills, made him the obvious choice to be the ANC's volunteer-in-chief during the defiance campaign," he said.

Before Zuma spoke, Mandela's grandson, Ndileka, told ANC supporters that his grandfather was "doing well" and that being among his close relatives in Qunu made him to "glow" and to be "full of jokes".

ANC secretary-general Gwede Mantashe, who described Zuma as an "intellectual", told the audience that for the duration of the lecture, they must address the president as "professor".

For his hour-long lecture, televised live on SABC2 , Zuma refrained from commenting on the stand-off that took place a few moments earlier between the ANC Youth League and police.

Earlier, a police officer at the scene said the idea was to only remove the four and not to charge them.

Many members of the public were excited to see a large number of ANC national leaders, including Billy Masetlha and national spokesman Jackson Mthembu.

Provincial police commissioner Simon Mpembe said police had not anticipated any disruptions at the venue.

"We deployed enough personnel to ensure the situation was under control.

"We are happy that there was free movement of those invited, as well as the uninvited ones, who watched proceedings from outside the venue.

"We want to thank the people of Thohoyandou for their good behaviour," said Mpembe.

Before the lecture, Zuma visited and addressed traditional leaders in the Sekhukhune and Vhembe districts.