"We are not going to open a case against anybody – they have declared a war and we are ready to fight," provincial league secretary Jacob Lebogo said on Wednesday.
He was one of the leaders who emerged with some bruises from the scuffle.
Media reports ahead of the event had predicted problems, given the party's recent expulsion of ANC Youth League president Julius Malema, who hails from Limpopo.
Provincial police spokesperson Brigadier Hangwani Mulaudzi said a group of people began blocking roads in the vicinity of the Holy Worship Church hall on Tuesday afternoon, ahead of Zuma's arrival.
About 300 people converged outside the church hall. Some carried banners with Malema's picture, singing: "Zuma is troubling us".
They became involved in a fight with security guards when they entered the hall at 4pm.
"Those people are anti-Zuma and came inside the venue and started singing anti-Zuma songs. Then the ANC security inside the hall contained them and assaulted them," said Mulaudzi, adding that the police were called in to defuse the situation.
"Five of them, who were among those singing anti-Zuma songs, were bundled into a police van and taken away from the venue. We then gave them a serious warning to refrain from causing problems in the area. They complied and were released on a warning," said Mulaudzi.
Zuma began speaking after 5pm but violence continued outside the hall during his address.
League provincial chairperson Rudzani Ludere and Lebogo said they were "harassed" by people dressed up as members of the Umkhonto weSizwe Military Veterans Association, who were specifically targeting them.
"The 'black painting' was done deliberately, as intentions were to find a way of sourcing hooligans from other provinces to come to the province wearing MKMVA combat [gear] to harass delegates and eye marked [keep an eye on] the leadership of the ANC Youth League …" said Ludere.
Zuma and delegates from the ANC's national executive committee had converged at the church for an address by Zuma on the life of former president Nelson Mandela as part of the party's centenary celebrations.
Delegates heard Mandela described as a selfless leader, who did not harbour ambitions to serve two terms in the ruling ANC.
Lebogo and Ludere said Zuma had discredited Limpopo Premier Cassel Mathale because he did not support Zuma's re-election.
He was "always threatening removal based on unfounded and unproved allegations [against Cassel]".
"Clearly, the assault to the ANC Youth League was pre-orchestrated, there was no point at any instance that their movements were not videotaped, even at the registration point," said Ludere.
The league in the province re-affirmed its view that Zuma would not be re-elected by their members, saying he had failed to develop other areas, but focused on "building New York City" in Nkandla, his hometown.
The league also apologised to the Mandela family over disruptions to the lecture.
"The ANC Youth League in Limpopo wishes to take forward our sincere and heartfelt apologies to president Nelson Mandela and his family on the unfortunate circumstances that nearly disorganised the lecture in his honour," said Ludere.
"We are further disappointed that the Mandela family was undermined in the lecture."
The presidency said it had no comment and the ANC has not responded to a request for comment. – Sapa