A crowd vandalised and set fire to a Waymo self-driving car in San Francisco, California, at the weekend amid growing tension in the city over driverless vehicles.
Police were called to the city's Chinatown at about 9pm on Saturday to find the car had been set alight in the most destructive attack so far on driverless vehicles in the US.
Michael Vandi, a witness who posted videos of the incident, told Reuters people in the crowd were setting off fireworks to mark the Lunar New Year when a person jumped on to the hood of the Waymo vehicle and broke its windscreen.
Others broke windows using skateboards and sprayed paint on the car, which was soon engulfed in flames.
Waymo said no one was in the car at the time and no injuries were reported, describing the incident as a “one-off event”.
The robotaxi was one of hundreds of the company’s fleet in San Francisco, said Waymo representative Sandy Karp.
“We are working closely with local safety officials to respond to the situation.”
The electric car, a Jaguar I-PACE, is equipped with 29 cameras and other sensors.
The San Francisco Police Department said it was investigating the cause of the fire, believed to have been caused by a firework being thrown inside.
No motive has been given for the attack.
While this is far from the first attack on self-driving cars, the severity of the incident indicates growing hostility towards them.
Last year, a vehicle operated by General Motors' Cruise unit struck and dragged a pedestrian for about six metres. And last week, a Waymo driverless vehicle hit a cyclist in San Francisco.
On previous occasions in San Francisco and Phoenix, Arizona, groups have disrupted the operations of self-driving vehicles, blocking their path, trying to enter the vehicles and jumping on them.
Videos that went viral showed people putting orange traffic cones on top of the vehicles to obstruct their sensors and forcing them to stop abruptly.
Waymo offers a driverless ride-hailing service in Phoenix and is working to expand the service to Los Angeles and Austin, Texas.
Completely driverless test vehicles, mostly from Cruise and Waymo, travelled nearly 5.3 million kilometres in California last year.