A rowdy crowd surrounded a Waymo vehicle in San Francisco’s Chinatown Saturday evening and set it on fire, police said. 

The San Francisco Police Department said a crowd of about 10 to 15 people surrounded the fully autonomous vehicle between Stockton and Grant just before 9:30 p.m. 

The mob graffitied the vehicle and smashed its windows before tossing a firework inside. The firework ignited, causing the vehicle to catch on fire. 

A spokesperson for Waymo said the vehicle was not transporting any riders and no injuries were reported. 

It remains unclear what motivated the crowd to destroy the vehicle. No arrests have been made as of Sunday. 

The Waymo spokesperson said the Mountain View-based company is working with local safety officials to respond to the situation. 

San Francisco police reminded residents on Sunday that use of fireworks in the city is prohibited because "they cause death, injury, and property damage." 

Fox News Digital has reached out to the San Francisco Police Department for more information.