Three police officers have been removed from usual duties after concerns over the use of force in a video circulating on social media.
The footage shows an officer using a baton after a row breaks out between a man and plain-clothed policemen in Upper Sutton Street, Aston, Birmingham.
West Midlands Police said after an initial investigation, the matter has been referred to the police watchdog.
The three officers have been redeployed to other work.
The video was posted on Sunday by police monitoring campaign group Netpol.
In a statement, West Midlands Police said: "We are aware of a video circulating on social media relating to arrests made by officers in Birmingham yesterday.
"We are quickly gathering as much information as possible and we will undertake an assessment of that information to understand exactly what has happened.
The force initially confirmed five of its neighbourhood policing officers had been involved.
However, later on Monday it said the investigation involved three officers, all of constable rank, who will be redeployed to other work but will not be engaged in duties outside a police station.
The matter has also been referred to the Independent Police Complaints Commission, the force said.
In a tweet, community campaigner Desmond Jaddoo, said: "This not the way to conduct stop & search or treat the public.
"Excessive disproportionate unjustified use force against the BME (black minority ethnic) community."
The force said a 20-year-old man arrested for a public order offence had been released while inquiries continued.
A 28-year-old male was cautioned for possessing cannabis.