NEW YORK (Reuters) - New York police were investigating a suspicious white powder at American Express headquarters next to the site of the September 11 attacks, the company said on Thursday.
There was no need to evacuate the building and business activities were not interrupted, company spokeswoman Joanna Lambert said.
U.S. authorities have been on alert for mail with white powder in it since 2001, when envelopes laced with anthrax were sent to media outlets and U.S. lawmakers, killing five people.
"Some suspicious envelopes were delivered to American Express here in our headquarters in New York. We contacted emergency services and the HazMat (hazardous materials) unit of the New York Police Department is examining the envelopes," Lambert said.
Last month, the U.N. missions of several countries received a letter containing white powder that turned out to be flour. At least 40 people were decontaminated as a precaution. Similar scares have hit New York-based companies and institutions over the years.
American Express, founded in 1850 as an express delivery company, is the largest U.S. credit card firm by purchase volume. Its headquarters in the World Financial Centre are across a highway from the site of the World Trade Centre that was destroyed in the attacks of September 11, 2001.
(Reporting by Daniel Trotta; Editing by Peter Cooney)