NEW YORK (AP) -- New York City Mayor Michael Bloomberg says he doesn't know why two threatening letters containing traces of the deadly poison ricin were sent to him.
The mayor did say one of the letters referred to his "anti-gun efforts." He also said Wednesday night that he did not feel threatened and that he was not going to walk away from "those efforts."
Police said earlier Wednesday the anonymous letters were opened Friday in New York at the city's mail facility and Sunday in Washington at an office used by his gun-control group, Mayors Against Illegal Guns. Both were addressed to Bloomberg and contained threats referencing the debate on gun laws.
Police say preliminary testing indicated the presence of ricin.
Ricin is a poison found naturally in castor beans.