Gun enthusiast sends poison threats to Obama, Bloomberg New York: President Barack Obama and Michael Bloomberg, the Mayor of New York, have been warned in threatening letters laced with the deadly poison ricin to stop campaigning for new gun control laws. ""If you take my guns, you should see what I'm going to do to you,"" the letters said. The anonymous author warned that government officials who tried to seize firearms ""will get shot in the face"." The Secret Service confirmed that a letter addressed to Mr Obama, which was intercepted at a mail processing office away from the White House, had tested positive for the poison. It was said by law enforcement sources to be identical to two others sent earlier to Mr Bloomberg in New York and the director of his Washington-based pressure group, which lobbies for new gun laws. A defiant Mr Bloomberg said on Thursday: ""I don't feel threatened."" Describing illegal gun use as ""a scourge on the country"," he said: ""We're not going to walk away from those efforts."" The author told Mr Obama, Mr Bloomberg and Mark Glaze, director of Mayors Against Illegal Guns, that he or she had a ""constitutional and God-given right"" to guns, which would be exercised ""til I die"." The letters added: ""You're not going to take my guns. You'll have to kill me before you take my guns,.""They are believed to have been sent by the same person from Shreveport, a city of about 200,000 people in the southern state of Louisiana. The FBI and intelligence officers from the New York Police Department (NYPD) are investigating.Mr Obama proposed sweeping new gun control laws after last December's primary school massacre in Newtown, Connecticut. They have so far been blocked by Republicans in Congress. Mr Bloomberg has spent millions of his $US25 billion ($25.8 billion) fortune backing the plans. The 71-year-old mayor's intervention provoked anger from the National Rifle Association, which warned members: ""He wants to impose New York City-style gun bans on you all over the country."" Wayne LaPierre, chief executive of the lobbying group, accused him of mounting a ""secret sting operation"."The letters contained a ""pink-orange oily substance"," which was found to test positive for ricin in tests at a forensics laboratory in Maryland, police said. Mr Glaze in Washington and a New York city employee were said to be unharmed. Ricin can be fatal if inhaled or digested in tiny doses. It has no known antidote. Three NYPD officers, who removed one of the letters from a municipal building, were examined after showing mild symptoms, which later abated.