Members of the Mongrel Mob and Black Power gangs had to be separated by police officers and security staff in Whanganui District Court on Wednesday.
Tempers exploded as a defendant had a charge of murdering Mongrel Mob member Kevin Neihana Ratana put to him and pleaded not guilty.
After making his plea, the defendant, who has interim name suppression, began yelling obscenities causing chaos as supporters of Ratana retaliated.
Police and security presence was already high in the courtroom that was full of tension with members of both gangs represented inside.
Half of them removed the defendants from the courtroom, while the other half removed Ratana's supporters from the court.