Women walking or exercising around the Hamilton Lake reserve are being warned to take care after a woman was grabbed at.
Police say the woman was approached by a man between 11 and midday on Thursday.
They say his conduct, and what he said to her, made the woman feel uncomfortable and when she walked away he followed her and tried to drag her behind a shed.
The man ran off when a passer-by intervened.
Police are appealing for any witnesses to the incident.