Several cars have been damaged after stones were thrown onto Broadway from the direction of the Kings Theatre.
Constable Vanessa Paki Paki of Stratford Police says four complaints have been received about the May 9 incident.
Police are reviewing camera footage taken at the time, but were unable to identify anybody involved. She urged people with any information to contact police.
Haley Tecofsky was driving down Broadway at around 8.15pm when she heard a big bang.
A rock had hit the back door of her car, next to where her toddler was sitting, and was just 30cm from hitting the child's window. She says the car had minor damage but the whole incident was upsetting.