A 26-year-old woman was seriously sexually assaulted after she left a Wyke pub.
She left the pub between 11.45pm and midnight and was walking down a snicket between Clare Road and Green Lane, Wyke, when she became aware of two men following her.
One of the men grabbed her and subjected her to a serious sexual assault.
They both then fled.
Police are appealing for information following the attack.
Acting Detective Chief Inspector Richard Holmes, of West Yorkshire Police’s Homicide and Major Enquiry Team, said: “Specially trained officers have been speaking to the victim.
“Unfortunately the victim did not manage to get a description of the suspects.
“A forensic examination of the scene has taken place and enquiries are ongoing.”
Anyone with information relating to the incident is asked to contact Bradford District Safeguarding on 101.