Uber blamed a self-drive car allegedly jumping a red light on "human error" - the day the new vehicles were launched onto the streets of San Francisco.

On Wednesday, a fleet of self-driving cars arrived in the American city amid controversy over whether Uber needs a permit to test out the pioneering technology.

Hours later, a driver-less Uber vehicle was filmed seemingly jumping a red light while other cars remained stationary.

But Uber insisted the incident was down to human error - claiming that the car had not been in autonomous mode at the time.

Uber first introduced the driver-less Volvo cars, available through uberX, to Pittsburgh in September.

Now the company has rolled out a number of the innovative vehicles in its hometown San Francisco.

But this has not been without controversy, with California regulators arguing Uber needs a permit to keep the vehicles on the road.

On Wednesday, the California Department of Motor Vehicles sent a letter to Uber ordering it to "cease the operations".

In a statement on its website, Uber asserted its belief that a permit was not required.

The company argued that the cars already require a person to constantly monitor and take control of the wheel, which does not meet the definition of autonomous.

"All of our vehicles are compliant with applicable federal and state laws," a company spokeswoman said.

On the same day, a video appeared on YouTube of a driver-less car purportedly jumping a red-light.

Meanwhile, another woman claimed a self-drive Uber had jumped a red light, almost hitting her own car.

Uber claimed the car in question had not been in autonomous mode at the time and was not carrying any passengers.

Rather, the company blamed the incident on "human error".

A driver has since been suspended.