Uber’s self-driving cars have been suspended in San Francisco after two vehicles were seen running red lights hours after the service launched.
The firm has blamed the violation on “human error”, saying the cars were not part of the pilot and that it had suspended the drivers in question.
But the California department of motor vehicles told Uber that if it does not “stop its launch and seek a testing permit” it will initiate legal action.
One video posted on YouTube shows a self-driving Uber driving through a crossing several seconds after the lights went red.
The second violation was captured in a photograph taken by a San Francisco writer which shows an Uber entering an intersection while the lights are red.
Uber wrote in a blog that it did not believe it needed a “testing permit” for the self-driving launch as the cars had people behind the wheel.
In a statement published by the Guardian, Uber said: “These incidents were due to human error. This is why we believe so much in making the roads safer by building self-driving Ubers. The drivers involved have been suspended while we continue to investigate.”
Uber first began testing self-driving cars in Pittsburgh in August. It was the first time members of the public could use self-driving cars in the US.