CCTV footage has captured a row between a group of men and a traffic warden who appeared to ride his scooter into them.
Members of the crowd allege he also lashed out with his radio and helmet during the altercation.
Police were alerted to the incident in Hackney, east London, on Monday at just before 2pm.
An onlooker said a scuffle broke out after the warden was confronted by local businessmen, including a group of Orthodox Jews, who said they would report him to the council.
Footage shows the warden swinging his helmet as he is surrounded by a group of men.
A Hackney Council spokeswoman said the warden, who was wearing a body camera, had been subjected to “intimidation” in the lead-up to the incident.
An onlooker alleged the warden “revved his motorbike and rode it straight” at one of the men in the crowd.
He said the man “fell on the floor and the motorbike fell on top of him”, leaving him shocked and bruised.
He also claimed the warden “just whacked” this man with his radio.
An onlooker said: “It was like a scene out of a movie. It was chaos. People were chasing and backing off scared.”
They allege the warden left and later came back, took off his helmet and some “tussling” took place. The crowd held him down on the ground and police arrived.
Scotland Yard said: “Four men, aged in their 20s and 30s, suffered minor injuries during the incident.
“A 30-year-old man was arrested on suspicion of grievous bodily harm and taken to a north London police station.
“He was subsequently bailed pending further enquiries to a date in mid-February.”
Hackney Councillor Feryal Demirci, cabinet member for neighbourhoods, transport and parks, said: “We are co-operating with police in their investigation of a warden, who is a contractor working for APCOA (parking management company).
“The warden’s bodycam footage shows he was subjected to significant and unprovoked levels of intimidation, threats and harassment in the lead-up to that which has also been captured on video by members of the public.
“He sustained a number of injuries for which he received hospital treatment, fortunately none of them was serious.
“We will be seeking to have charges pressed against some of those involved in the incident against the warden.”