Police are continuing to investigate a violent attack at the Hamilton Kmart amid growing concerns thieves are getting more brazen and aggressive.
A video on social media shows two women who appear to be leaving the store without paying for handfuls of goods attacking security guards.
One pulled a female security worker's hair and refused to let go, while another woman lunged at bystanders and a worker with what appeared to be kitchen tongs.
New Zealand Security Association chief executive Gary Morrison told Checkpoint security staff were facing these kinds of incidents on a "very regular" basis.
"It's quite confronting and I think people are getting more aggressive and they are prepared to take that aggression out on security staff and other people as well, shop workers, visitors etc," he said.
Security staff working on loss prevention were being involved in brazen attempts at theft on a daily basis, Morrison said.
He said theft was a massive problem for the country and thieves were well aware that security workers could do little to stop them.
"You have the power to defend yourself without using excessive force so that is effectively what we are limited to, we don't have powers similar to the police, we can't make arrests.
"Obviously the safety of our staff is paramount but it's not just the safety of staff it's the safety of even the offenders, of other people there, floor workers etc."
Morrison said security staff received safety focused training that taught them not to put themselves at risk.
He said retailers contracting security services often determined how guards approached incidents of theft.
