A woman endured a horrific sex assault by a lone attacker who was hiding outside a flat.
The woman was returning from a night out to the flat in Boothroyd Green, Dewsbury, at 11.30pm on Thursday October 16.
On reaching the top of the three-story block of flats, a man who had been crouching in wait threw her to the floor, punched her in the face and sexually assaulted her.
She bravely managed to fight off the suspect, who ran off in an unknown direction.
He is described as approximately 5ft 8ins tall and was wearing dark clothing.
PC Lyndsey Booth said: “This was a nasty attack on a lone female which has left her very distressed.
“We are keen to hear from anyone who was in the area at the time and may have witnessed this attack or seen the suspect running from the scene.
“Please contact me on 101 or ring Crimestoppers anonymously on 0800 555111.”