Shuttle buses operated by Apple and Google have been attacked with what law enforcement described as “unknown objects,” several of them receiving damages like broken windows. No injuries were reported however.

Buses for employees commuting to and from San Francisco were attacked between January 12 and January 16 on 280, with a report from Mashable revealing that one incident took place near Woodside, while another one happened outside of Los Altos Hills.

Four separate buses had their windows broken following the attacks, and while many believe culprits used rocks, others called them “rubber rounds.”

Apple acknowledged the attacks in an internal email to employees, saying that it’s rerouting the shuttle buses to avoid similar incidents in the future.

Subject: Coaches temporarily being rerouted

Due to recent incidents of broken windows along the commute route, specifically on highway 280, we’re re-routing coaches for the time being. This change in routes could mean an additional 30-45 minutes of commute time in each direction for some riders.

As always, the safety of our employees is our first priority. We’re working closely with law enforcement to investigate these incidents and we’ll notify you as soon as the coaches are able to return to the regular route. Thank you for your patience and understanding.

The Apple Commute Team

At least one shuttle bus belonging to Google has also been involved in a similar incident, and the California Highway Patrol is now investigating. Just like in Apple’s case, someone threw objects at the moving bus on Highway 280, breaking the windows, again without causing any injuries.

As it’s the case of Apple, Google decided to change the route of its buses, at least until the police come to a conclusion following the investigation.

In an interview for the San Francisco Examiner, Doug Bloch, the political director of the Teamsters Joint Council 7, said the attackers used “pellet guns” and confirmed that no one was injured.