LOS ANGELES (AP) — Police detained two 15-year-olds who they say were drinking and shooting water beads while riding in a self-driving Waymo after the company alerted law enforcement in Northern California and remotely forced the vehicle into a parking lot, officials said.

San Mateo police officers stopped and searched the vehicle Monday afternoon after a Waymo representative contacted them, department spokesperson Jeanine Luna said.

Photos from a bystander shared with a local TV station showed the teens hanging out of the Waymo’s windows. Police say they determined they were drinking in the car and shooting Orbeez, which are soft, water-absorbent polymer beads, out into the streets.

Waymo pulled the vehicle over into a parking lot and let officers know they were doing so.

“The occupants were not locked in and had every ability to exit the vehicle,” Luna said in an email.

Officers were able to communicate with a Waymo representative through the vehicle’s communication system during the stop, Luna said.

The San Mateo Police Department posted about the incident on social media and warned people about underage drinking and the danger of water bead guns.

The post garnered more than 150 comments, with some expressing concern about surveillance and whether it was acceptable for Waymo to deliver the teens to the police.

Waymo did not respond to emailed questions about how the company was alerted to the teens’ behavior and if the teens were informed the car was being pulled over.

According to a support page online, cameras inside Waymos are used to make sure cars are clean, find lost items, and provide help in case of emergency. Facial recognition is not used to identify individuals, it said.

“Our Support team may review video under certain circumstances, including after an issue is brought to our attention,” the page said. “Occasionally, in more urgent circumstances, Support may access live video during a trip.”

A Waymo vehicle had another run-in with the law last month in San Francisco, where a burglar broke into a yoga studio and stole activewear before making his getaway in the autonomous vehicle.

Jaimie Ding, The Associated Press