The thieves have knocked down three of their 22 victims, whose ages have ranged from 55 to 88, in the past two months. Nine attacks have occurred in the past week.
Police said the crimes were "outrageous" and have issued a warning to pensioners to avoid walking near the kerbs of pavements.
In the latest incident, Elsie Beeston, 88, who is 4ft 8in tall, escaped unharmed after a motorist mounted a kerb and snatched her handbag, containing pounds 50 cash, as she was walking home. Mrs Beeston was shocked but unhurt.
But the victim of the most serious incident, aged 77, is still in hospital with a broken pelvis and ribs after being struck by a car which mounted the pavement and hit her from behind.
A 55-year-old woman - the youngest of the victims - is recovering from back and hip injuries after being thrown over the bonnet of a car whose driver made off with her bag.
Other pensioners have been dragged to the ground after a man in a car grabbed their handbags or shopping bags.
Detective Inspector Ray Galloway, leading the investigation, said it was thought that more than one man could be responsible, though all the attacks followed a pattern.
He said: "These offences are absolutely outrageous. The men carrying out these attacks are desperate, reckless cowards who need to be caught before they kill.
"They are preying on old ladies who they know will be carrying handbags or shopping bags.
"I would urge all elderly women in Liverpool not to walk too close to the kerbs on pavements, and never stand close to the road when waiting for a bus. It sounds like crazy advice, but we are dealing with the craziest kind of criminal."Reuse content