There will be an independent investigation into what appears to be a violent arrest involving four police officers at Byron Bay, on the New South Wales north coast.

There was outrage on social media last week when vision emerged of a naked 16-year-old boy being arrested in January.

Four police officers were shown holding him on the ground, and the video appeared to show the boy being repeatedly struck with a baton and screaming for help.

Police have said the teenager was violent and under the influence of drugs, and promised an internal review.

But complaints from the public have resulted in the state's Law Enforcement Conduct Commission pledging to investigate the incident and the associated conduct of police officers.

A second video emerged this week of an 18-year-old woman being arrested near the town's Main Beach car park.

Police have confirmed the woman was knocked unconscious during the incident, but alleged she tried to bite a female officer and later spat at an ambulance officer.

The 18-year-old woman was charged with affray, assaulting police and an ambulance officer, and offensive conduct, while a 21-year-old man who became involved in the incident will face similar charges.

Women protest 'police violence'

Today about 20 women marched through Byron Bay to protest against police behaviour.

An 18-year-old woman is arrested near Byron Bay's Main Beach car park. ( Facebook )

Protestor Adaja Black told ABC North Coast police training was not good enough.

"It's completely unacceptable behaviour by our police force," she said.

"They're supposed to be protecting us and presenting duty of care.

"Police officers are obviously not trained in the psychological skills needed to approach people in that situation."

Police officers assaulted 170 times, superintendent says

Police superintendent Wayne Starling said his officers used force as a last resort.

He said officers working in the Tweed-Byron Command had themselves been assaulted more than 170 times in the past year.

"[In] America, some of these incidents that have occurred lately, police would have shot the people involved," Superintendent Starling said.

"Our police have used verbal communication skills, they've used capsicum spray on one occasion and that hasn't worked.

"On two occasions in the last two weeks they've used tasers to try to restrain people [and] they've ripped the barbs out of their chests and they still come at the police.

"At the moment I have 30 police that can't strap on a gun. Fifteen of those police have physical injuries.

"They come to work each day. Many of them have slings, many of them have broken bones, and several have black eyes at different times.

"That's the community they're policing at the moment."

Mixed opinions in local community

The issue has generated heated debate on social media, including the ABC North Coast Facebook page.

"Good on the police … maybe this will be a lesson she learns from, but probably not." — Vanessa Crockett Hislop "That's because police believe legislation gives them exemptions for morality. No accountability for their actions because the law says it's lawful. Lol funny old system we have, but hey, just be thankful in a way this ain't America." — Loki Hunter "The cops are in the right here. Have a think about how it all started, alcohol and being drunk in public." — Robert Denning "Excessive force, 2 police officers against one female teenager. If you can't do the job properly find another job." — Russell Lambe

Police have told the ABC no charges have been laid against the 16-year-old boy involved in the first arrest.