New York, May 30 - Two threatening letters sent last week to New York Mayor Michael Bloomberg contained the poison ricin, the city's police department announced Wednesday.
One of the letters was received last Friday at a New York municipal office and the other arrived at an office in Washington that houses the Mayors Against Illegal Guns, an advocacy group Bloomberg founded to push for stricter gun control laws.
Bloomberg never came in contact with the letters.
The letters contain threats against Bloomberg over his policy against the unrestricted sale of firearms, an effort in which he has become more active after the Newtown, Connecticut, elementary school massacre last December.
Preliminary tests performed on the letters confirmed the presence of ricin, a deadly poison.