New York City Mayor Michael Bloomberg said he did not feel threatened or angry after two anonymous letters, believed to be carrying the deadly poison ricin, were sent to him.
The letters threatened Mayor Bloomberg and referred to the debate on gun control, according to police.
Mr Bloomberg has been one of the country's most visible gun control advocates since the shooting of 20 young children and six adults at a Connecticut school
When asked whether he was angry about the letters, he said: "No I'm not angry. There are people who I would argue do things that may be irrational, do things that are wrong. But it's a very complex world out there. And you just have to deal with them."
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The letter calls for an end to harassment, abuse, and impunity in a world "ripe for change".