It is believed a man in his 40s was verbally racially abused and assaulted inside the toilets of a pub in Bromsgrove Road, in Hagley.
The victim was not injured in the assault, which is believed to have taken place between 8.30pm and 11pm on Saturday, July 28.
The suspects are described as four or five white men, aged between 20 to 24-years-old. One was described as being 5ft 10 and of an average build, one was wearing a t-shirt and blue jeans, and one was wearing a green/grey t-shirt. It is believed he may have later been picked up in a white VW Beetle.
Investigating officer PC Chris Royle said: "We are appealing for witnesses to this incident, or to anyone who may recognise the description of those involved.
"We're particularly concerned that the motivation for this was racial and we're keen to identify those responsible."
Anyone who witnessed the incident is asked to call West Mercia Police on 101, quoting incident reference 22/66906/18.
Alternatively, information can be provided anonymously to Crimestoppers on 0800 555111 or by visiting www.crimestoppers-uk.org.