A 44-year-old woman has been sexually assaulted in Bathgate in West Lothian.
Police said she was approached by a man riding a bike as she walked southwards on Kirk Road between midnight and 01:00.
He got off the bike and physically and sexually assaulted her. He then left in an unknown direction.
Detectives said the “frightening ordeal” had left the victim badly shaken. They appealed for anyone who with information to contact them.
The suspect is described as a white man with a slim build. He is in his late 20s to early 30s and may possibly have ginger hair and a ginger beard.
He was riding a blue/black bike with white markings.
Det Con Lee McCall of Livingston CID said: “We’re eager to trace this man as soon as possible and I would ask anyone who was in the Kirk Road area around this time and saw anything suspicious to contact us.
“Likewise, anyone who may recognise the description of the man is urged to come forward immediately.”