A building on Facebook’s Menlo Park campus, which houses both Instagram and Facebook employees, has been evacuated Tuesday night after a reported bomb threat.

Menlo Park police confirmed on Twitter that its bomb squad was on the scene and conducted a search of the building, but later said it didn't find any explosives or suspicious packages. The threat was was initially called in by the New York Police Department’s Crime Stopper unit, according to a local San Francisco NBC report. Authorities in Menlo Park were then alerted. The rest of Facebook’s campus was not told to evacuate at the time of this writing.

Concerns about safety at tech campuses in the Bay Area have risen over the past year, especially following a shooting at YouTube’s San Bruno campus in April. It’s unclear how many people were working when the call came in, sometime in the late afternoon on the West Coast.

Update, December 12th, 00.15AM ET: Added information about the bomb squad’s search.