New York, May 30 (IANS/EFE) 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.
The letter sent to New York was opened at a postal reception center for the Mayor's Office located on Gold St. and contained threats against Bloomberg.
Three members of a New York police unit that deals with emergencies handled the letter and had to be treated last weekend for slight symptoms of exposure to ricin, the police reported.
The letters have a return address in the state of Louisiana.
Authorities waited to announce the receipt of the letters until the results of the initial tests were in hand. Tests were performed at the National Bioforensic Analysis Center in Maryland.
Authorities believe the same person sent both letters, and the NYPD along with the FBI counterterrorism division is investigating their origin.
In mid-April a letter containing ricin was sent to President Barack Obama and on the same day another letter containing the same poison was set to Sen. Roger Wicker.
A third suspicious letter was sent to the office of Sen. Carl Levin.