A woman has been repeatedly punched in a random attack by a man whose motive has baffled police.
The 37-year-old was assaulted in Gipton by a man who cycled past her - but he did not steal anything from her, did not speak and was not known to her.
The incident happened at around 9pm on Thursday night.
West Yorkshire Police said:
"At 8.54pm police were contacted by the ambulance service who were attending Brander Road, in Gipton, where a 37-year-old woman had been found with serious injuries.
"The victim received serious facial injuries and was taken to hospital for treatment.
"She had been walking along South Farm Road towards the junction with Brander Road when a male cycled past her on a bike before getting off and punching her in the face a number of times.
"He said nothing to her and no demands were made for property.
"He was described as white, aged 17 to 20, wearing a hooded top with the hood covering his face."
Detective Inspector James Entwistle, of Leeds District CID, said:
“The victim has been left with very serious facial injuries and we are carrying out enquiries to identify the person responsible for this nasty attack.
“There doesn’t appear to be any clear motive at this stage and we would like to hear from anyone who witnessed the incident or who has any information that could assist the investigation.”
Anyone with information is asked to contact Leeds District CID via 101 quoting crime reference 13180574800 or call the independent charity Crimestoppers anonymously on 0800 555 111.