Scientists who understand the potential of artificial intelligence have a significant fear: killer robots, also known as autonomous weapons.

In August, more than 100 technology leaders, including Tesla and SpaceX CEO Elon Musk, signed an open letter calling on the United Nations to ban the development and use of artificially intelligent weaponry. Musk has tweeted that he fears a global arms race for artificial intelligence will cause the third World War.

Monday, the famous physicist Stephen Hawking warned of the importance of regulating artificial intelligence: "Unless we learn how to prepare for, and avoid, the potential risks, AI could be the worst event in the history of our civilization. It brings dangers, like powerful autonomous weapons, or new ways for the few to oppress the many," he said at the Web Summit technology conference in Lisbon.

On Nov. 2, hundreds of AI experts from Canada and Australia joined the chorus, submitting open letters to their respective governments urging them to support the United Nations move to ban autonomous weapons.

"As you know, AI research — the attempt to build machines that can perform intelligent tasks —has made spectacular advances during the last decade. The evolution of classical AI, bolstered by rapid advances in machine learning, has revived the ambitions of the AI community to build machines that can carry out complex operations with or without human oversight or intervention," the Canadian community's letter to Prime Minister Justin Trudeau says.