More than 1,500 people have put their name to a formal letter of complaint sent to Chief Constable David Thompson regarding the way an incident on March 1 is being investigated.
In the letter, the force is accused of inaction in dealing with the crime, with fears there could be “institutional racism or unconscious bias” against the Bangladeshi community.
Mr Thompson said he would be addressing concerns directly with the letter’s authors.
He has also been called by West Midlands Police and Crime Commissioner David Jamieson to give an update at a public board meeting next week.
Abdul Hafiz, 44, and his 38-year-old brother Abdulla Al Mamun claimed they had asked revellers holding a lockdown party at a property near their home in Lord Street, Palfrey, to keep the noise down, when things turned ugly.
They said they were chased down the road by a number of attackers and beaten with fence panels used as weapons during the ordeal.
Mr Hafiz was knocked unconscious for around 15 minutes and suffered a fractured hip, while Mr Al Mamun was left with facial injuries.
West Midlands Police confirmed they were investigating the incident.
But, in the letter, sent by Walsall activist and Labour NEC member Mish Rahman and signed by 1,591 people mostly from the town, it is claimed that police initially failed to attend on the night when the alarm was raised by family members; and that officers only attended after paramedics made a second call asking for police assistance but no arrests were made.
It also says that it took more than 48 hours for one of the brothers to be interviewed to obtain a witness statement; and that the second brother had not been spoken to a week after the incident due to officers awaiting an interpreter.
Quote from the letter include:
“What is inarguable is that West Midlands Police has failed in its duty of care.
“There is still an opportunity for the mistakes over the way Abdul Hafiz and Abdullah Al Mamun to be addressed. More importantly, lessons need to be learned very quickly to ensure there is no repeat.”
A West Midlands Police spokeswoman said: “Chief Constable Dave Thompson will be responding directly to the letter’s authors.”
Mr Jamieson said: “I have asked the Chief Constable to provide an update on the incident at my public board meeting on Tuesday to help reassure the public.”