A woman in Arizona has been hit and killed by a self-driving Uber car.

It's believed to be the first time an autonomous vehicle has killed a pedestrian.

Uber says it is cooperating with the authorities.

The victim has not yet been named by the Tempe Police Department.

A woman in Arizona has died after being hit by a self-driving car operated by Uber in what is believed to be the first time a pedestrian has been killed by an autonomous vehicle.

One of the transportation firm's vehicles struck a woman in Tempe late Sunday night, and she died of her injuries at a hospital, the Tempe Police Department said in a statement.

The vehicle was in self-driving mode at the time of the crash, police said. The news was first reported by ABC 15.

The vehicle was travelling at around 40 miles per hour at the time of the collision, a spokesperson said, and did not appear to slow down when the pedestrian entered the road.

The incident appears to be the first time a pedestrian has been killed by an autonomous vehicle, and it is sure to ignite debate about the ethics, safety, and legal culpability of the technoogy. Proponents of the technology tout it as a far safer alternative to human-driven cars.

A male driver was previously killed while using Tesla's semiautonomous "Autopilot" mode, though he had ignored seven safety warnings.

Uber has paused all its self-driving-car operations in Tempe, San Francisco, and Toronto, WPXI News reports.

The victim was walking outside of a crosswalk when she was hit, police said. She was not yet named because her next of kin had yet to be notified. There was a vehicle operator behind the wheel of Uber's car at the time of the crash.

The exact circumstances of the crash were not yet known.

In a brief statement provided to Business Insider, Uber confirmed someone had died and said the company was cooperating with investigators.

A spokesperson said: "Our hearts go out to the victim’s family. We are fully cooperating with local authorities in their investigation of this incident." The company did not immediately provide further details about the deadly incident.

In a statement Tempe police said:

"We wanted to provide an update to the Uber accident that occurred overnight on Mill Ave. just south of Curry Rd. The vehicle involved is one of Uber’s self-driving vehicles. It was in autonomous mode at the time of the collision, with a vehicle operator behind the wheel. The vehicle was traveling northbound just south of Curry Rd. when a female walking outside of the crosswalk cross the road from west to east when she was struck by the Uber vehicle.

"She was transported to a local area hospital where she passed away from her injuries. Her next of kin has not been notified so her name is not being released at this time. uber is assisting and this is still an active investigation."

The National Transportation Safety Board is investigating the crash, it said on Twitter.