Children and young adults are more likely to die as a result of a traffic accident than from any other cause, according to the World Health Organization (WHO).

This high risk for the ages between 5 and 29 signals "a need for a shift in the current child and adolescent health agenda which, to date, has largely neglected road safety," the Geneva-based UN health agency said on Friday.

Only 33 countries have laws on child restraint systems for cars that are in line with the WHO's best-practice criteria, including limits on age, weight or height.

Overall, 1.35 million people of all ages die every year in road accidents, according to the WHO's latest global road safety report.

Although the annual total has slightly increased since the year 2000, the rate of road deaths as a share of the population has fallen slightly.

According to the WHO, this is a result of the increasing number of countries that implement speed rules and alcohol limits, as well as laws on helmets, seat belts and child seats.

However, progress has been uneven.

While the number of traffic deaths has fallen in nearly 50 wealthy and middle-income countries since 2013, there is not a single low-income country where the situation has improved.

In Africa, the fatality rate from road accidents is 26.6 deaths per 100,000 inhabitants per year, far higher than Europe's rate of 9.3.