The Secret Service says the White House mail screening facility has intercepted a letter that is similar to the ones sent to New York Mayor Michael Bloomberg that were laced with the deadly poison ricin.
The agency, which protects the president, announced Thursday they have turned over the letter to the FBI's Joint Terrorism Task Force for testing and investigation. The agency says the letter was addressed to the White House.
Hours earlier, New York City police said two letters sent to Mayor Michael Bloomberg tested positive for ricin.
One of the letters was opened Friday at a New York mail processing facility and the other was opened Sunday at the Washington office of Mayors Against Illegal Guns - a Bloomberg-founded organization.
A police spokesman said both letters threatened the mayor and referred to his anti-gun group. The spokesman said police officers who came in contact with the New York letter showed minor symptoms of ricin exposure.
Last month, ricin-tainted letters were sent to President Barack Obama, a U.S. senator and a Mississippi state judge. A suspect in that case is in custody.