The future is now - and endangered.

Increasingly autonomous, gun-totting robots developed for warfare could easily fall into the hands of terrorists and may one day unleash a robot arms race, a top expert on artificial intelligence told AFP.

"They pose a threat to humanity," said University of Sheffield professor Noel Sharkey ahead of a keynote address Wednesday before Britain's Royal United Services Institute.

Intelligent machines deployed on battlefields around the world — from mobile grenade launchers to rocket-firing drones — can already identify and lock onto targets without human help.

We really should have invented time travel first, huh?