Thames Valley Police is appealing for witnesses to an assault in Stony Stratford, Milton Keynes, on Wednesday (15/6).
At around 8.30pm, two males riding on a motorcycle kicked the victim, a woman in her fifties, in the leg as they drove by on Willow Lane.
They were also abusive to other members of the public and threw bricks at dogs.
The males are described as white and aged between their mid teens and early twenties.
They were wearing dark clothing and full-face balaclavas, and riding a purple motocross-style bike.
Investigating officer PC Ryan Michel, based at Milton Keynes police station, said: “It has been reported that these two males have been riding a purple motocross-style bike around the Stony Stratford area for about a week, causing anti-social behaviour, riding on public footpaths and speeding on the road.
“I would also like to speak to anyone who has a dash-cam and was in the local area at the time of the assault to check the footage in case it may have captured something that could assist our investigation, as well as anyone with CCTV footage.
“To report information, please call 101 or visit our website, quoting reference number 43220262215.
“Alternatively, for 100% anonymity, contact the independent charity, Crimestoppers, by calling 0800 555 111 or via its website.”