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,

One of the suspicious white-powder envelopes sent to an ICE office in Manhattan this week included a menacing note saying it was delivering “karma” for migrants, law-enforcement sources told The Post.

Suspicious white powder that forced the ICE field office in New York City to evacuate is not hazardous, the FBI said Friday.