A message was circulated to parents of Shrewsbury Academy pupils yesterday telling them to mention the planned incident to their children "if appropriate to do so".
The message said: "Good afternoon. Police have been passed information that a fight is planned to take place in the Quarry this Friday afternoon/evening involving children and young people. Knives and adult involvement has also been mentioned.
"Whilst we are unable to confirm this intelligence, there will be a large, visible police presence in both the Quarry and town centre.
"Can we ask that this be mentioned to your children, if you see it appropriate to do so.
"Given the nature of the information received, children and young people should also be made aware that a robust policing approach will be taken, with zero tolerance shown towards anyone behaving in an anti-social or threatening way.
"Any information received by yourselves can be passed on via your local policing teams or the police at Shrewsbury via 101."
Shrewsbury town centre and the Quarry has been the scene of numerous violent incidents and anti-social behaviour in recent weeks, although after at least three arrests were made and the shops reopened, criminal behaviour had appeared to be settling down.
Police have been contacted for a comment.