A wild early morning brawl involving at least 20 tradies in high-vis gear has erupted in the street, with everyone involved now out of a job and police investigating.

Workers began unloading a flurry of punches and kicks outside Meriton’s Castle Grange construction site in Sydney’s northwest on Tuesday.

WATCH THE VIDEO ABOVE: Wild tradie brawl erupts at Sydney worksite.

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One worker was filmed by onlookers as he was clobbered over the head a number of times with a hard hat.

Police were called to Sexton Ave in Castle Hill about 7am but said “most” had dispersed by the time they arrived.

“Officers have been informed that the brawl involved two apparent groups wearing hi-vis clothing and construction attire,” NSW Police said.

A 43-year-old man and another aged 55 were treated by paramedics before being taken to Westmead Hospital with minor injuries.

It is unclear what sparked the violence.

Meriton said contractors involved in the fight were now out of a job.

“Meriton promotes safety and does not condone any violent or threatening behaviour on its job sites, whether employees, subcontractors or visitors,” a spokesperson said.

“No direct Meriton employees were involved in the incident that took place today on the street, outside of its Castle Hill construction site.

“Appropriately, the local police were called who have since intervened and we have ascertained that there were no serious injuries.

“The contractors involved in the fight have been immediately terminated.”

Workers were back on the tools on Tuesday afternoon.

The police investigation is ongoing and anyone with information should contact Crime Stoppers.