Facebook Inc evacuated a few buildings at its headquarters campus in Menlo Park following a bomb threat, a company spokesman said
Everyone is safe and the company is looking into the incident, the spokesman said in an emailed statement to Reuters.
Menlo Park Police Department said a building at 200 Jefferson Drive has been evacuated and the bomb units are on the scene going through the building.
However, it did not specify which Facebook building in Menlo Park was evacuated.
YouTube was another Silicon Valley company that faced security threat in the recent past.
In May, a woman opened fire at YouTube's headquarters in San Francisco, wounding three people before she shot herself dead.