Blood-stained floor tiles, broken chairs, stun grenades and bloodied delegates characterised the ANC Eastern Cape's elective conference on Saturday night.
One delegate was taken to hospital on a stretcher, while seven others were rushed from the scene by ambulance.
Some delegates demanded that the conference be cancelled, while others vowed revenge.
"How can we continue when our delegates are in hospital. We cannot let this conference continue. We will go to court if we have to," one delegate said.
Some delegates had earlier cried foul over the registration process, with claims of unauthorised members being allowed to participate in the event.
The party demanded that all delegates produce identity documents before entering the venue.
ANC provincial executive committee member Mlibo Qoboshiyane told reporters that the violence erupted during the adoption of credentials at around midnight, when delegates demanded to know what happened to some of the branches and their members.
"Because... we [have] too [many] altercations when it comes to that, there was a proposal that there must be division of the house, which did not sit well with the branches," he said.
"They started to sing up until there was division of the house. Then we saw chairs flying and people get injured. Some had to rush [out] for their safety, they were trampled upon and indeed there were injuries that happened."
He said the conference would continue despite the incident.
Three hours earlier, police fired stun grenades to disperse a group of ANC members near the gates of the International Convention Centre, where the conference was being held.
Police on the scene told News24 that a group of ANC supporters attempted to force their way past the gate to the centre.
The group was divided among those in support of provincial chair Phumulo Masualle and those for secretary Oscar Mabuyane.
ANC National Executive Committee delegate Lindiwe Zulu came out after that incident to assure the media that the situation outside was not a reflection of any chaos inside.
She said the adoption of credentials was being debated "vigorously and smoothly" by delegates.
On Saturday morning, the party's communications official ushered in secretaries of the eight regions to the media room, which was situated 14 floors away from the conference.
One by one, each regional secretary assured that media that their delegates had been satisfied with its delegation's accreditation.
Police presence had to be intensified at the conference after Masualle's supporters forced their way into the conference hall on Friday night. The delegates in support of Mabuyane and Masualle clashed and police were called in to diffuse the matter.
On Saturday, provincial executive committee member Andile Lungisa claimed Mabuyane was rigging the numbers. Lungisa told News24 that "friends and girlfriends" were accredited for the conference instead of branch approved delegates.
Another delegate from OR Tambo region, Mluleki Dlelanga promised delegates at the gates of the venue that something will be done about 'bogus' delegates.
In the early hours of Sunday morning Mabuyane accepted nomination for the position of chair nomination while Masualle as well as Lungisa were not present to accept their nominations.
PEC member Stella Ndabeni-Abrahams tweeted that Masualle was injured running away from the violence.
During nominations the electoral commission said despite some absences, a quorum was reached - according to ANC constitution.
It was announced that 951 delegates were present for nominations and voting. However shortly after the nominations, the proceeding were suspended until Sunday morning for Masualle to accept or decline his nomination.
NEC delegate Zizi Kodwa confirmed that that presidential hopeful and current ANC deputy president Cyril Ramaphosa would close the conference on Sunday. -- News24