Scenes of chaos from San Francisco’s Chinatown spread across social media Sunday after a mob vandalized and set fire to a Waymo self-driving car using a firework on Saturday evening. Waymo, owned by Google parent company Alphabet, has been offering Californians a 24/7 taxi service in driverless cars since last summer.

“Waymo Vehicle surrounded and then graffiti’d,” the San Francisco Fire Department said on social media hours later. “Windows were broken, and firework lit on fire inside the vehicle which ultimately caught the entire vehicle on fire.”

Photos uploaded by the fire department, which later reminded people that using fireworks is banned in San Francisco, showed the vehicle in flames and later its charred remains.

Police are investigating, and no arrests had been made as of Monday afternoon, San Francisco Police Department spokesperson Paulina Henderson told The Washington Post.

Officers responded to the fire at about 8:50 p.m. local time, the police statement said. When the officers arrived, the unoccupied car was “engulfed in flames,” according to the statement, which added that there were no reports of injuries.

Aaron Peskin, president of the San Francisco Board of Supervisors, told NBC News that the incident was “terrible” and “extremely dangerous.”

“Buildings could have been lit on fire, people could have been hurt and most importantly, this was the day of the Chinese Lunar New Year,” Peskin said. “This is one of the most important days for families, there were thousands and thousands of tourists here, partaking in the events.”

A Waymo spokesperson told Reuters that the passenger-less car was moving along a street in Chinatown when people surrounded it. Later someone threw a firework inside, setting the fire, the company said.

“The vehicle was not transporting any riders and no injuries have been reported,” the company said.

Although cars without drivers have become a common sight on San Francisco’s winding and sloping streets, there are long-standing tensions between the city’s residents and the cars.

Still, rarely have driverless cars been set on fire.

A Waymo vehicle struck a cyclist last week in the Potrero Hill neighborhood, resulting in minor injuries, the Verge reported. The Waymo passenger was unhurt, and the cyclist left the scene on their own.

Driverless cars have caused major concerns in San Francisco by disrupting first responders on multiple occasions, including driving into scenes cordoned off by caution tape and striking a firetruck responding to an emergency, The Post previously reported.

Last year, a robotaxi operated by Cruise — a Waymo rival — rolled over a pedestrian and dragged her about 20 feet, after which the California Department of Motor Vehicles suspended its operations. Days later, the company said it would suspend all driverless operations in the country to examine its process and earn back public trust.

In four videos uploaded by witness Michael Vandi, who heads Addy AI, an AI company, a man who is using his jacket to cover his face can be seen scribbling on the back of the car with what appears to be a sharpie. Others in the crowd appear unmasked. An unidentified voice encourages others to light the vehicle on fire.

The atmosphere directly outside Hua Long Trading, a shop selling cigarettes, snacks and other daily items on Jackson Street, appears charged.

Once the car is set on fire, however, people appear to back away from the vehicle. The Post could not access footage of the moment when the firecracker was thrown inside the car.

Vandi told Reuters in a direct message on X, formerly Twitter, that people were celebrating the Lunar New Year on Saturday evening by setting off fireworks. He said he saw a person jump onto the hood of the vehicle and break its windshield, and another later jumped onto the hood as the crowd clapped. Vandi could not be reached for comment Monday morning.

“That was when it went WILD,” he wrote. “There were 2 groups of people. Folks who encourage it – and others who were just shocked & started filming. No one stood up – i mean there wasn’t anything you could do to stand up to dozens of people.”