Police are appealing for information after a 12-year-old girl was approached by a man as she walked along a footpath.
The incident happened between 3pm to 3.15pm in Yarrow Valley Way, Chorley on Friday.
Officers say the man approached her from behind, grabbed her round the hips and then touched her bottom before running off in the direction of Coppull.
He is described as white, around 5ft 7in tall, of slim build and around 40-years-old. He had short dark hair going grey at the back and was wearing a long sleeved green checked shirt and baggy blue jeans with white trainers. He was also described as wearing black leather gloves.
PC Craig McCabe of Chorley Police said: “This was a very upsetting incident for the girl involved but I would like to reassure parents and local school pupils that incidents like this are rare and we are determined to trace the man involved.”