A father and son have been arrested over a violent early-morning street brawl at a construction site on Tuesday.

Two men were taken to hospital with cuts and a broken nose and cars were damaged when up to 50 men in hi-vis gear began trading punches and kicks in Castle Hill, Sydney just before 7am, police said.

Amid the violence outside Meriton’s Castle Grange construction site on Sexton Ave, one worker was filmed being clobbered over the head a number of times with a hard hat.

Know the news with the 7NEWS app: Download today

Authorities were told the fight involved two groups, with most people involved having left before police arrived.

One man suffered a broken nose and another needed stitches for a cut above his eye.

Both were taken to Westmead Hospital and discharged a few hours later.

Two men aged 22 and 44 were arrested after handing themselves into Castle Hill police on Wednesday morning.

“I’m grateful that they have turned up this morning because we were about to knock on their door,” Detective Superintendent Naomi Moore said.

“I’m told that (they’re) father and son.”

Moore said the pair are speaking with detectives and “I expect charges will be laid very shortly”.

Police understand the arrested duo were subcontractors who had been laid off on Friday before returning to the worksite on Monday, allegedly sparking a fist fight in which two men sustained minor injuries.

“I think on the Monday there was probably some frustration and anger from their termination on the Friday,” Moore said.

“And whether they’ve gone there to resolve it, one would argue they haven’t as they’ve attended with hammers.

“Thankfully they put those down before they engaged in a fight with the contractors.”

Moore alleged the two men returned to the same site on Tuesday, this time with others who had not worked there previously, and “up to 50 people have engaged in a melee on the street”.

Cars were also damaged during the brawl, with one vehicle’s bonnet dented and another’s back windscreen smashed.

“(The brawl) blew my mind if I’m honest,” Moore said.

“I’ve not seen anything like that before.

“It’s appalling and, as I said, that’s a residential street, this is where people live. To be woken to that, it’s not OK.”

Police said they are looking for up to 11 other people involved in the fight.

“Not only do we have the footage from the actual incident ... there’s significant footage in nearby locations to that scene that is much clearer and we will very clearly be able to identify those parties,” Moore said.

“We encourage those people to come forward ... before we go and knock on their door because that will be happening.”

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.

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

Anyone with information should contact Crime Stoppers.