A Black Power member who made an "offensive gesture" at a group of passing Mongrel Mob members spurred a midday attack in Rotorua on Monday.
A police spokeswoman said police received multiple reports from members of the public about an assault at the intersection of Old Taupō Rd and Devon St at 12.45pm on Monday.
She said four to six people were involved and initial reports indicated one person was beaten by a group of people who had arrived in multiple cars.
The group fled when police arrived and no arrests were made as police tended to the victim.
Acting Rotorua area commander Inspector Phil Taikato said the isolated incident was a man by himself who made an offensive gesture to members of the Mongrel Mob.