Hundreds of prominent figures from technology, politics, and media are urging a global halt to the development of “superintelligence,” artificial intelligence systems capable of surpassing human intelligence.

A statement published on Wednesday titled “Statement on Superintelligence” has drawn more than 29,000 signatures. The document calls for “a prohibition on the development of superintelligence, not lifted before there is 1.) broad scientific consensus that it will be done safely and controllably, and 2.) strong public buy-in.”

Among the signatories are major tech leaders, including Apple cofounder Steve Wozniak and Virgin Group founder Richard Branson. Also signing were AI pioneers Yoshua Bengio and Geoff Hinton, widely regarded as “godfathers” of modern artificial intelligence.

Political and public figures also appeared on the list, such as former Chairman of the Joint Chiefs of Staff Mike Mullen and former National Security Advisor Susan Rice. Conservative commentators Steve Bannon and Glenn Beck were included, as well as British royals Prince Harry and Meghan. Former Irish President Mary Robinson also signed the statement.

The group warned that while AI has led to innovations across industries, the rapid pursuit of more advanced systems carries major risks. The statement said AI progress has “raised concerns, ranging from human economic obsolescence and disempowerment, losses of freedom, civil liberties, dignity, and control, to national security risks and even potential human extinction.”

The statement also cited data from the Future of Life Institute, which found that only 5 percent of US adults support continuing the “fast, unregulated” development of superintelligent AI. The same survey found that 64 percent of Americans believe “superhuman AI” should not be created until it is proven safe or controllable, or not created at all. 73 percent support “robust regulation” on advanced AI systems.