A local builder was among dozens of people captivated by surreal scenes in Upper Hutt as a road roller rammed several cars in an incident police say could have ended in tragedy.

George Robins said there had been some gossip going around that a subdivision development on Eastern Hutt Rd was allegedly being used for burnouts despite ongoing bids to restrict access to the site.

"I was sober driving that night and when I was coming back past that road I saw heaps of headlights."

He parked his Lancer some distance away and crossed a paddock to take a closer look, immediately noticing the smell of burnt rubber.

"You could see the skids on the road."

There was rubber from tyres that had blown out and the black skid marks ran off the seal digging welts into otherwise tidy grass.

Robins heard a man telling the people gathered to leave and it sounded the group gathered were being cheeky back, he said.

"I definitely heard him say, 'you need to get out of here'."

Then surreal scenes unfolded as a road roller allegedly started pushing cars around.

"I was in awe," Robins said. "I was like 'holy cr*p'."

"My mind was going like a 100 miles an hour. I didn't know what to think."

But he said he was not scared because it seemed like cars rather than people were allegedly being targeted by the road roller.

He also pointed out that he believed the road roller was moving at a low speed.

People did start scrambling back to their cars, he said.

"I thought, 'I've seen enough, I am out of here'," he said.

"I walked back to my car and took off."

Police say one person sustained leg injuries and another suffered facial injuries after an altercation that ensued.

Two men were arrested after the incident, both of which have interim name suppression after appearing in court yesterday.

"As this matter is before the courts police are limited in what further information can be provided," a police spokesperson said previously.

"However, it is clear this was a serious incident which had the potential for tragedy.

"We urge anyone who notices activity that concerns them to contact police straight away, rather than taking actions which might put themselves and others at risk."

National MP Judith "Crusher" Collins has previously declined to comment on what happened.

She introduced a law in 2009 allowing police to seize boy racers' cars and destroy them.

The bill earned Collins the nickname Crusher.