A knife-wielding man exposed himself to children near Wenlock Junior School on Thursday during lunch time.
The offender was in a walkway between Leygreen Close and Beaconsfield when he pulled what appeared to be a knife from his pocket and exposed himself to six children in the playground.
He made off towards Devon Road and the children immediately reported the incident to staff at the school.
Det Con Sam Toombs, who is investigating the incident, is keen to speak with anyone who was in area when the offence took place and may have seen the offender.
The offender is described as being a white male, between 50 and 60 years old, around five feet seven inches tall, fat, with short grey hair which was balding on top, ‘Harry Potter’ style round glasses, wearing a black and grey jacket with green stripes down the front, and riding a bright green bike.
Call Det Con Toombs on 01582 394132, the non-emergency 101 number, or text information to 07786 200011.
Alternatively contact independent charity Crimestoppers, anonymously, on 0800 555 111, or online at crimestoppers-uk.org.