Police are seeking a man who ripped a woman’s hair from her scalp.
Officers have released a photo of the suspect who carried out the unprovoked attack in south London.
The victim, a 31-year-old woman, got off a Route 119 bus outside East Croydon railway station, at around 6.45pm on 18 December.
Police said the suspect pulled the woman’s hair, resulting in some of it being ripped from her scalp.
He then punched her in the back of the head, causing her to fall.
Detectives described it as a prolonged and racially-motivated attack, which left the woman with facial injuries.
Detective Constable Becky Hughes said: “Tackling violent crime, especially against women and girls, remains our main priority.
“This was an entirely unprovoked assault which continued whilst the victim was lying on the ground.
“I would urge anyone who was there, or who recognises the person whose image we have released today, to come forward. We need to identify and speak with him.”
Anyone with information should contact police on 07880 429486 or on 101 quoting reference CAD 5448/18Dec.
Another option is to call Crimestoppers anonymously on 0800 555 111 or tweet @MetCC with any information.