A Sydney man has been left brutally injured after he was attacked overnight with what is believed to be a machete.

The victim, aged in his 40s, was seen wandering near a strip of shops on Aurora Drive in Tregear in Sydney's west at around 4am, covered in blood and barely conscious.

He had just been attacked with a weapon that is believed to be a machete in a unit across the road.

A group of tradies passing by spotted the victim and came to his aid.

He was treated by paramedics before being taken to Westmead Hospital with serious stab wounds to his head and hand.

Shopkeepers here are fed up with the violence that comes from residents living at these flats across the road, some told 9News.

Shoplifting incidents and assaults allegedly take place regularly in this area.

Kebab shop owner Bilal Syed told 9News he was threatened with a knife just a few months ago.

"All of a sudden you're working and things can go wrong, but I didn't expect someone to pull a knife on me," he said.

Officers attached to Mt Druitt Police Area Command established a crime scene at a unit on Bransfield Street.

No arrests have been made and an investigation is now under way.

Anyone with information is urged to contact police or Crime Stoppers on 1800 333 000.

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