The campaign headquarters for US Democratic presidential candidate Hillary Clinton was evacuated last night after a white substance was discovered in an envelope.
The substance was first discovered by two interns at a campaign office in Manhattan and was taken to Clinton's Brooklyn headquarters, triggering the evacuation of the 11th floor, a New York Police Department spokesman said.
A total of four people were exposed to the substance, police said, though there have been no injuries or reported illnesses.
NYPD Lieutenant Thomas Antonetti told AFP: "The preliminary investigation determined that it was negative in terms of containing a hazardous substance."
He said the Department of Health was conducting further evaluation to determine the nature of the substance.
Lt Antonetti said the envelope also contained writing, but no death threats.
"We're trying to determine what the substance was. For right now, we can at least rule out any poisonous or deadly nature of the substance," he said.
