The Future of Life Institute is continuing its quest to save the human race from artificial intelligence. In an open letter published by the organization, top leaders are teaming up to ask for a ban on autonomous weapons.

The letter already has hundreds of signatures, including prominent names such as Steven Hawking, Elon Musk, Steve Wozniak, Eric Horvitz and Noam Chomsky.

(Related: The Future of Life Institute’s previous warning about AI)

“Autonomous weapons select and engage targets without human intervention,” the letter stated. “Artificial Intelligence (AI) technology has reached a point where the deployment of such systems is—practically if not legally—feasible within years, not decades, and the stakes are high: autonomous weapons have been described as the third revolution in warfare, after gunpowder and nuclear arms.”

According to the institute, while AI has the potential to benefit humanity, it also has the ability to destroy it, and developing autonomous and artificially intelligent weapons could be the beginning of that destruction.

“The key question for humanity today is whether to start a global AI arms race or to prevent it from starting,” according to the letter. “If any major military power pushes ahead with AI weapon development, a global arms race is virtually inevitable, and the endpoint of this technological trajectory is obvious: autonomous weapons will become the Kalashnikovs of tomorrow.”

In addition, the institute says that autonomous weapons are much cheaper to manufacture than nuclear weapons, and if produced, it is only a matter of time before they are in the hands of terrorists. “There are many ways in which AI can make battlefields safer for humans, especially civilians, without creating new tools for killing people,” the letter stated.