Three quarters of child car seats inspected by Greater Manchester Police in a safety crackdown were either faulty or not fitted properly.
The force’s road policing unit spent a day stopping vehicles as part of Project EDWARD (European Day Without A Road Death) in an effort to improve road safety in the city region.
And of the 20 car seats looked at by officers, 15 needed some kind of remedial action.
Sgt Dennis Delve said: “The number of vehicles that needed remedial action to their seat belts to make them safe was much higher than I had anticipated.
"I would urge anyone travelling in a car or using a child seat to make sure their safety restraints conform to current safety advice.”
Project EDWARD manager James Luckhurst said: “The volume of road safety faults and offences detected by officers in a relatively short period of time illustrates the unnecessarily high risks some drivers are willing to tolerate on their journeys.
"It also highlights the tremendous value of police enforcement activity in reducing the number of people killed and seriously injured on our roads.
“It was abundantly clear during this operation that officers taking part were there with one aim – to prevent harm to young children who are our most vulnerable road users.
"That is central to the aims of Project EDWARD, and we appeal to any driver willing to take a safety risk by using an insecure child seat, or choosing not to use one at all.
"Your children rely on you to keep them safe when they’re on road journeys, so please do everything you can to reduce the risks they face.”