Three Invercargill men were taken to hospital on Saturday morning following what police described as a "nasty" attack.
Sgt Wing-Wah Ng said five women and one man, travelling in a red van, allegedly attacked the group, in a silver Ford Falcon, between midnight and 1am in central Invercargill.
The victims, all aged in their 20s, received varying injuries including facial wounds, lacerations and broken teeth, he said.
The alleged offenders, aged 19 to 39, were arrested and charged with injuring with intent.
They will remain in police custody until they appear in the Invercargill District Court tomorrow.
Alcohol was a factor but Sgt Ng did not understand what caused the group of six to attack the others.
Inquiries were continuing and police wanted to hear from anyone who saw the incident.