The Transport Department on Tuesday reminded parents and guardians to choose suitable car seats or seat belts for their children before a new regulation takes effect.

From November, children below the age of 8 must use a child restraining device (CRD) in private cars, unless their height reaches 1.35 metres.

According to government data, about half of the traffic accidents which injured or killed children under the age of 8 involved private cars.

A chief engineer with the department, Eddy Wu, said children should use a CRD which is suitable for their height and weight.

"The CRD has a specific range of applicable weight and age... you have to choose the appropriate type of CRD for your child," he said.

"If [the child] is below 2, because his bones are not well-developed, you may have to choose some kind of rear-facing CRD to protect them."

Wu said the requirement for private cars is only the first step, and the government may look into whether the rule can be expanded to cover other transportation in the future.