A 60-year-old ended up in hospital after being attacked on a Leeds bus.
It happened at 8.30pm on March 6 on a number 4 service, which runs between Seacroft and Pudsey.
As the bus left Seacroft Green Shopping Centre, the victim became involved in a fight and ended up with serious cuts to his face, which required hospital treatment.
Officers investigating the attack have released CCTV images of a man they want to identify.
The suspect was described as a white, aged 30 to 40, "scruffy looking", with red/orange mullet-like hairstyle, shaved at the sides but longer on top and at the back.
Anyone who recognises the man shown in the images or who has any information should contact DC 6432 Kate Hutton at Elland Road on 101, quoting crime reference 13200119860 or online via www.westyorkshire.police.uk/101livechat
Information can also be given anonymously to the independent charity Crimestoppers on 0800 555 111.
In February West Yorkshire Police started travelling to "antisocial behaviour hot spots" to talk to dozens of kids who have been seen throwing stones at buses and other vehicles in the likes of Crossgates, Seacroft, Killingbeck and Whinmoor.
