A gang brawl inside Tokoroa District Court on Tuesday forced staff and the judge to lock themselves in a safe area of the court, where the fight made the walls move.
Tracy Klenner from the PSA, which represents court staff, said the union had been raising security problems with the Ministry of Justice for some time.
"The public and the judiciary were scared for their safety and they locked themselves in the exit rooms at the back of the court rooms."
"The violence was of such a nature that there were people getting thrown about and it was enough to make the walls move about in the courts."
She said staff had been debriefed and filled out health and safety reports but they were still frightened for their safety.
"There were no uniformed police or court security there on the day."
Ms Klenner said there was also no scanner at the entrance to the court.
A local lawyer who was in the courtroom at the time and did not want to be named said children were out in the foyer crying and had to be rushed into an office for their protection.
She said while there were security staff at WINZ and ACC offices, small courtrooms around the country were left to fend for themselves.
Another lawyer who was in court at the time, Maryanne Crapp, said the court registrar locked the courtroom door and stopped people in the public gallery from leaving, while banging, shouting and swearing could be heard outside.
She described the senior registrar's fearless actions as a heroic.
In a written statement, a police spokesperson confirmed no officers were at court at the time, but because the station was near they were able to respond quickly.
"As a result, five people were arrested, of which four are facing charges, while inquiries are continuing into a number of other individuals who are believed to have been involved.
"Police is also continuing to work with court staff and management to ensure all visitors and people attending court are kept safe in future."
A ministry spokesperson said it would be following up on the incident, but could not make further comment because the matter was before the courts.
Ms Klenner said the issue was not limited to Tokoroa and on the same day there were 21 court rooms around the country with no security staff present.
Last week there was a similar incident at Kaikohe where some people were armed with weapons but security staff were able to difuse the situation.