Volkswagen diesel cars are the most popular cars on the road in the United States and the first-ever electrified models in the world.
But they are also being increasingly abused, with the potential to be more dangerous, according to a new report from the Center for Auto Safety.
The center, which has been tracking the issue for decades, found that diesel cars in North America have been involved in more than 5,000 accidents in the last decade, most involving the electric car.
The report found that in the states with the most accidents, such as California, Texas, Florida, Ohio, Pennsylvania and Illinois, there was a significant percentage of the accidents involving the diesel car.
For many of the crashes, the diesel was not even registered, the report found.
The vehicles were found to be operating on an unregulated basis and the owners were not required to register them.
The report found diesel cars to be the cause of more than a third of the fatal crashes.
In some states, they were the cause in less than a fifth of those crashes.
In the past decade, the number of fatal crashes involving electric cars has increased dramatically, and there have been several reports of fatalities involving electric vehicles.
The number of such deaths rose by 20 percent in the decade from 2014 to 2015, according the report.
In 2016, Volkswagen was fined $13 million for a similar accident involving a diesel vehicle in Spain.
The company said it was reviewing its diesel vehicle programs and would provide more information about the issues identified in the report next year.
It said it would also update its emissions regulations.