An 18-year-old has been arrested after a brazen stabbing attack that ended with the victim hiding inside a Kmart at a shopping centre in Sydney’s west yesterday. 

Witnesses recalled seeing a 22-year-old man lying bleeding inside Dawson Mall at Mount Druitt at 5pm yesterday.

“I saw a guy lying down on the floor and there was blood everywhere, it was pretty shocking,” witness Arcelie told 9News.

At about 4pm today, an 18-year-old was arrested at a home in North Rooty Hill and taken to Mount Druitt Police Station for further inquiries.

No charges have yet been laid.

The incident began when a verbal altercation erupted between a group of men.

The group separated, but came across each other again 15 minutes later in the car park outside Kmart in Westfield Mount Druitt, opposite Dawson Mall. 

A physical altercation broke out, and two men, aged 22 and 17, were stabbed.

NSW Police said the 22-year-old man, who was stabbed in the back and suffered a punctured lung, then ran inside the Kmart to get away from the group and seek medical assistance.

Early reports falsely indicated the man was stabbed inside the shopping centre. 

Police were called and arrived at the scene to find the 22-year-old with stab wounds to his upper body.

Emergency responders moved everyone to the back of the store and held them there while working to treat the man’s injuries.

Eventually, customers were let outside, with police snapping a picture of everyone’s ID to form a witness list. 

He was taken to Westmead Hospital with critical injuries.

A 17-year-old was treated for a slash wound to his hand and face.

He was taken to Nepean Hospital in a stable condition.

A third man in his 20s was treated for minor injuries.

Police believe everyone involved was known to each other, and suspect the offenders had fled the scene before they arrived.

Detective Superintendent Darrin Batchelor said investigators believe the incident is related to recent “postcode” wars in the area.

“It seems to be a street gang type of altercation,” he said.

“Quite frankly, I can’t understand where you might have an issue with someone’s postcode … and their answer to that would be to carry knives, which is totally unacceptable.”

He appealed to anyone in the community with information to reach out and asked concerned parents to contact police if they believe their sons are involved in postcode war-related street gangs. 

“I have no doubt there are a number of parents in this community right now that are worried that their young sons are involved in these postcode wars, and may end up in jail, in hospital or worse,” Batchelor said.

“I appeal to those parents, if you have concerns of your son being involved in these street gangs for whatever reason, whether it’s peer pressure or otherwise, contact police and we’ll be able to assist those young people.”

Officers have seized several items of interest in relation to the stabbing, including a butter knife.