Scores of Hyundai and Kia vehicles lack basic security features and should be recalled, as a growing number of thefts have created a "safety crisis" on roads across the U.S., a group of state attorneys general says.

A letter sent by the attorneys general of 17 states and the District of Columbia to the National Highway Traffic Safety Administration on Thursday urges the federal government to intercede to prevent a national problem they say is continuing to accelerate.

"Thefts of these Hyundai and Kia vehicles have led to at least eight deaths, numerous injuries and property damage, and they have diverted significant police and emergency services resources from other priorities," the AGs wrote.

"We call on NHTSA to exercise its authority to order a mandatory recall or ensure Hyundai and Kia institute a voluntary recall."

According to the letter, a thief can easily hotwire certain Hyundai and Kia vehicles manufactured between 2011 and 2022 by removing the steering wheel column cover and turning the keyed ignition with a USB cable. These vehicles also lack engine immobilizers, which prevent a car from being started unless it receives an electronic signal from the key.

These particular vulnerabilities came into more widespread use since 2021 after a number of TikTok users posted videos of the technique to social media.

Federal regulators say about 3.8 million Hyundais and 4.5 million Kias are affected.

Thefts of Hyundai and Kia vehicles have exploded recently. Los Angeles saw an 85% increase in Hyundai and Kia thefts in 2022, while Minneapolis says it saw thefts of the two makes jump by 836% last year.

The perpetrators, who are often minors, drive recklessly and sometimes crash, the attorneys general said, and attending to both the thefts and the crashes diverts law enforcement and emergency response resources from other needs.

"Kia's and Hyundai's failure to install standard safety features on many of their vehicles have put vehicle owners at risk," California Attorney General Rob Bonta said in a tweet. "It is unacceptable that our communities should be forced to shoulder the cost of Kia's and Hyundai's failures."

A NHTSA spokesperson told NPR via email that law enforcement authorities had jurisdiction over any criminal conduct, and that NHTSA has repeatedly met with the two car companies to discuss the thefts and receive updates.

"NHTSA will continue to monitor this issue, spread awareness of further updates to local authorities, and lend its expertise in efforts to strengthen motor vehicle safety," the spokesperson said.

In an emailed statement to NPR, Hyundai said it was "committed to ensuring the quality and integrity of our products" and pointed to several measures it had taken in response to the thefts, including making engine immobilizers standard on all vehicles starting in November 2021 and reimbursing customers for the purchase of steering wheel locks. Hyundai also said it had partnered with AAA insurance companies to insure the affected vehicles in most states.

In February, Hyundai and Kia announced along with federal regulators that they would begin offering a free software upgrade for millions of vehicles without immobilizers over the following months. Hyundai said on Sunday that its software upgrade for affected vehicles is currently available at all Hyundai dealerships.

Kia told NPR it continues "to roll out a free, enhanced security software upgrade to restrict the unauthorized operation of vehicle ignition systems and we are also providing steering wheel locks for impacted owners at no cost to them."

The attorneys general said the software patch wouldn't be enough, though, since it may not work for all affected vehicles and doesn't come with the same legal requirements on the companies that a recall does.

Kia also responded to the notion of a recall, saying that "because there is no defect in the security features in any of these vehicles and because these specific models comply fully with all applicable federal standards, a recall is neither appropriate nor necessary under federal law."

A larger group of attorneys general wrote to Hyundai and Kia last month, urging the company to take "swift and comprehensive action" in response to the thefts.