A video has gone viral online depicting a wild brawl at a Newcastle fast food restaurant, with fire extinguishers set off during the violent altercation.

The video shows a group of boys, one masked, approach a McDonald’s on King Street on October 31 and spray the store and security guards with fire extinguisher foam.

One boy lifts an extinguisher above his head before slamming it to the ground.

The clip was uploaded to Facebook on Friday and has already amassed more than 85,000 views.

An employee from the restaurant, who wished to remain anonymous, said acts like this one are commonplace over the weekend.

“This is just typical of the place late at night,” the worker told the Newcastle Herald .

“It is out of control, they come like moths to a flame.

“The staff are definitely scared.”

The extinguishers are believed to have been stolen from a store nearby.

The employee said when working on a Friday or Saturday night employees “are just waiting for something to happen”, and often people under the influence of drugs and alcohol can get violent.

“We have seen people get followed into the toilets and bashed, not long ago a guy nearly lost his eye,” the worker said.

“There are four security guards on every Wednesday, Friday, Saturday and Sunday but even that isn’t enough.

“It’s out of control.”

A spokeswoman for the McDonald’s restaurant said it was working with local police to keep its employees and patrons safe.

“The safety off our crew and customers is our number one priority,” she said.

“We have a number of security measures in place at this restaurant and a close working relationship with local police to ensure our staff and customers are kept staff.”

However, Newcastle City crime manager Detective Inspector Steve Laksa said police had not heard about the fire extinguisher incident from staff or employees.

Police said they have identified three persons of interest since the video went viral online.