Police said today they were responding to an "active shooter" at YouTube's offices in California as social media images showed employees evacuating the campus.
San Bruno police warned on Twitter to stay away from the area housing the headquarters of the Google-owned video sharing service near San Francisco.
"We are responding to an active shooter. Please stay away from Cherry Ave & Bay Hill Drive," the police department tweeted.
Google tweeted: "Re: YouTube situation, we are coordinating with authorities and will provide official information here from Google and YouTube as it becomes available.