A woman was sexually assaulted in the early hours of the morning.
The 23-year-old was attacked by a man in the Love Lane area of Pontefract on Friday.
The incident happened between 3.30am and 4am.
And police are now appealing for witnesses.
Det Insp Tim Hunt, of Wakefield CID, said: “We are conducting initial enquiries into this report and specially trained officers are supporting the 23-year-old victim.
“She has reported being seriously sexually assaulted by an unknown man who then made off.
“Following the incident the victim attended Pontefract Hospital and informed staff who contacted police.”
Anyone with information should call police on 101 or Crimestoppers, anonymously on 0800 55111.