Envelopes containing an unidentified white powder that were found at a government building in New York City did not contain any dangerous substances, officials said.

Envelopes containing white powder was opened inside a federal building in lower Manhattan, according to a source familiar with the matter, prompting a police response. The five envelopes were discovered in a mailroom inside 26 Federal Plaza,

A New York City building housing an Immigration and Customs Enforcement facility was evacuated after unknown white powder in multiple envelopes was found at the complex, authorities announced on Thursday.