Clinton headquarters evacuated to powder letter

The headquarters of the campaign of Hillary Clinton in New York was evacuated Friday night (local time) after it was discovered an unknown white powder in an envelope.

Four people have been exposed to the powder and to be examined. It was not yet clear the white stuff is exactly.

A week surfaced after the attacks of September 11, 2011 in the United States letters containing a powder that caused anthrax. Five people thus died.