CCTV footage has been released of a woman shoulder-barging a pensioner into an oncoming bus.
The attacker, who had two children with her, slammed the victim towards the moving double decker and walked away as she lay sprawled on the ground.
Police released footage of the assault in Pimlico, central London, showing the victim, who is in her 60s, being hurled towards the side of the bus.
The pair had a "verbal exchange" in a branch of Tesco Express in Warwick Way at around midday on May 29 last year, and the victim was shoulder-barged by the woman but uninjured.
Minutes later as she stood waiting at nearby traffic lights on Vauxhall Bridge Road, the attacker barged her again, this time towards the path of an oncoming bus.
The victim suffered grazes and bruising to her ankles, shins and knees, a cut to the top of her head and a muscle injury to her shoulders.
Detective Constable Samantha Edwards said: "This was an unprovoked assault which could have had much more serious consequences.
"A number of inquiries have been undertaken to locate the person responsible.
"If you recognise this woman I would ask you to contact police immediately.
"It goes without saying that the victim has been deeply affected emotionally by this whole incident."
Anyone with information is asked to contact the Serious Crime Unit based at Westminster on 101 or tweet @MetCC, or to remain anonymous call Crimestoppers on 0800 555 111.