North Carolina is suing eight vaping companies for allegedly targeting children as customers, state Attorney General Josh Stein said Tuesday.

The state, which is already suing industry leader Juul, is now going after some of its smaller competitors for allegedly using flavors, marketing strategies and inadequate age verification systems to sell to underage kids. The new suits target Beard Vape, Direct eLiquid, Electric Lotus, Electric Tobacconist, Eonsmoke, Juice Man, Tinted Brew and VapeCo.

"There is a vaping epidemic among high schoolers and middle schoolers in North Carolina and the United States," Stein said. The lawsuits aim to "shut down their operations targeting young people in North Carolina."

The new actions follow a lawsuit by the state against industry leader Juul in May, alleging that the company targeted young consumers and misrepresented the potency of the nicotine in its products.

On a conference call announcing the lawsuits, Stein referenced an ad on Instagram from Eonsmoke that he said was clearly targeted at children, but he said the other companies engaged in similar practices. Eonsmoke was also sued by Massachusetts Attorney General Maura Healey in May.

An attorney representing Eonsmoke said the company "has had robust age verification for years and its typical customers are in their 20s and 30s," even for flavored products.

The lawsuits come as vaping and e-cigarette products are facing increased scrutiny for the possibility that they are getting children addicted to nicotine and that they cause health issues. Stein mentioned recent cases in Illinois, where officials reported the first death attributable to vaping-related lung issues last week.

"We simply have no idea what the long-term health implications of these products are, and people who are using them are essentially turning themselves into guinea pigs," Stein said.

Stein said the new cases are similar to the state's suit against Juul and that "discussions are ongoing" with Juul about possible injunctions in that case.

Juul launched an action plan last November that the company said was aimed at preventing young customers from using its products. The company is partially owned by Altria, which is exploring a possible merger with Philip Morris International.

The company said Tuesday it has shut down some of its social media accounts and enhanced its online age-verification process, among other measures.

"We share the Attorney General's concerns about youth vaping, which is why we have been cooperating with his office and why we have taken the most aggressive actions of anyone in the industry to combat youth usage," Juul said.

The Electric Tobbaconist said 90% of its customers are over the age of 25 and that it has an "extensive" process to verify the ages of its customers.

"We absolutely affirm that these products don't belong in the hands of children," the company said.

The other companies sued by North Carolina did not respond to CNBC's requests for comment.