Thirteen envelopes filled with white powder have been sent to the Wall Street Journal.
Police and the fire department’s hazardous materials team were called, but the powder was found to be harmless.
The envelopes were addressed to executives of Dow Jones, the newspaper’s publisher.
Three executives received them, while 10 more were found in the post room. They had Tennessee postmarks.
The incident had echoes of 2001, and the anthrax scares that followed the 9/11 attacks.
Email pged@pressgazette.co.uk to point out mistakes, provide story tips or send in a letter for publication on our "Letters Page" blog