Seattle police searched for explosives at Amazon.com`s headquarters after a threatening letter was found at a company building just north of the city`s downtown district, but found nothing, authorities said on Monday.
Amazon building security contacted Seattle police at 10:30 a.m. local time (1830 GMT) after staff found a note inside a bathroom at one of the buildings that make up Amazon`s sprawling headquarters, police said, without disclosing the contents of the note.
A few hours later, police said officers "have not found any indications the threat was credible," but were investigating who left the note.
The exact building was not identified, but police said it was on the 400 block of Terry Avenue North, where the most prominent Amazon buildings are located.
Police said some employees were evacuated while arson and bomb squad teams, along with explosive detection dog teams, searched the area.
Amazon did not return calls seeking comment.
According to Seattle tech news site GeekWire, Amazon`s Day 1 South building was closed because of the threat and some employees had returned home to work, citing sources close to the situation.
Day 1 South is at the center of Amazon`s headquarters in the South Lake Union neighborhood. The online retailer and cloud computing company is the biggest employer in the area, with thousands of staff in several buildings.