A suspicious device, later ruled a hoax, placed outside the federal building in downtown Oakland prompted evacuations Wednesday afternoon.
At about 12:40 p.m., the Federal Protective Service watched an individual place the device at the base of a flag pole in the plaza next to the federal building, FBI Assistant Special Agent in Charge Jonathan Blair said.
"It's got a lot of characteristics that are concerning to us, and so we're working slowly and diligently to do our diagnostics, use our tools, use the technology that we have," Alameda County Sheriff's Office Lt. Ray Kelly said during the investigation.
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Portions of streets in the downtown area near the federal building were closed for roughly five hours while the bomb squad examined the device, which was later rendered safe and called a "hoax device", the Alameda County Sheriff's Office said.
The device included a note for law enforcement and officials said whoever put it there wanted to elicit this type of response.
"In looking at the evidence there was a specific message for law enforcement that was left," Kelly said, adding the evidence has been collected by the FBI.
Officials said whoever is responsible could face "weapons of mass destruction" charges.