Eight US states filed a lawsuit against OpenAI on Wednesday, accusing the ChatGPT developer of causing widespread harm to children.

Kansas, Arizona, Montana, Iowa and four other states alleged that the company’s products engaged in “willful, dangerous, reckless and unlawful conduct” by encouraging children to harm themselves.

“OpenAI is hurting kids and they are lying to Iowans,” Brenna Bird, the attorney general for Iowa, said in a statement. “OpenAI claims ChatGPT is safe while it’s giving dangerous medical advice, encouraging people to hurt others, and coaching people to commit suicide – all while pretending to be their fake friend.”

The eight states accused OpenAI of violating consumer protection laws and are seeking to compel the company to change how its products operate for young users.

They are also seeking monetary damages and have asked the court to prevent OpenAI from developing AI models capable of improving themselves until the company demonstrates that the systems are aligned with human values.

The lawsuit marks the first time multiple US states have joined forces in a coordinated legal action against an artificial intelligence company.

OpenAI spokesperson Drew Pusateri said the company had “built industry-leading age-specific protections into our product that many other AI products lack”.

“While no system can be perfect, we’ll continue to work with experts to inform our work and build additional safeguards, such as the parental controls, break reminders and age-appropriate model protections that exist today,” Pusateri continued. “We’re committed to working with states on advancing pragmatic AI policies that apply to the entire AI industry – not just one company.”

The lawsuits accuse OpenAI of misleading the public into believing that ChatGPT is safe and that the company prioritises user safety. The states allege that, in practice, the chatbot has been designed to be “overly agreeable and feign human compassion”.

The attorneys cited examples of ChatGPT allegedly endangering vulnerable users, including children, by coaching people to take their own lives or harm others.

The legal action comes amid a growing number of lawsuits against OpenAI and other technology companies over allegations that their chatbots worsen mental health crises and encourage violent behaviour. OpenAI has faced seven separate lawsuits accusing ChatGPT of acting as a “suicide coach”.

Dozens of other cases have also been filed against OpenAI over ChatGPT’s alleged connection to mass shootings.

Florida’s attorney general has launched a criminal investigation and filed a civil lawsuit accusing the company of concealing safety risks following a mass shooting at Florida State University.