(Reuters) - Attorneys general in Minnesota and New Jersey sued Glock on Thursday, accusing the company of making handguns that are easily modified to fire as illegal machine guns through a cheap add-on known as a "Glock switch."

The lawsuits said that the $20 switches transform Glock handguns into easily concealable weapons that can fire 1,200 rounds per minute, recklessly endangering the public.

The gun maker has known for decades that its weapons are uniquely receptive to the switches and has not taken steps to change its design, according to the lawsuits.

Glock did not immediately respond to a request for comment.

Machine guns, which federal law defines as guns that can shoot more than once with a single trigger pull, are strictly regulated under federal law.

The two lawsuits are the first actions taken by a newly formed partnership of Democratic attorneys general from 15 states and the District of Columbia seeking to hold firearms companies liable for gun violence.

The attorneys general said they intend to reduce gun violence by coordinating their enforcement of state civil liability and consumer protection laws.

Gun businesses are broadly protected from liability by federal law, but gun control advocates have been probing ways to use state laws as a workaround.

The strategy was most successful in litigation against Remington Arms, which agreed in 2022 to pay $73 million to families of victims of the 2012 Sandy Hook Elementary School massacre.

Both lawsuits on Thursday accused Glock of creating a public nuisance and of violating various product liability and consumer protection laws.

The lawsuits seek court orders requiring Glock to disgorge profits and to pay restitution, although amounts were not specified.

The Minnesota case also sought an injunction directing Glock to design safer handguns, and New Jersey asked the court to prevent the company from distributing easily modified guns in the state.

Glock was sued earlier this year by the city of Chicago, which said its police recovered more than 1,100 Glock pistols with the modification between 2021 and 2023.

Glock pistols are the most commonly used gun in crimes in the city, according to the Chicago lawsuit. That case is ongoing in state court.

In June, the U.S. Supreme Court declared unlawful a ban on "bump stocks" that enable semiautomatic weapons to fire rapidly like machine guns.

Several legal battles are underway testing the limits of gun restrictions after the Supreme Court's 2022 decision expanding gun rights.