
A letter addressed to President Barack Obama tested positive for ricin, and authorities arrested a suspect, stoking alarm in Washington on Wednesday after an earlier scare over poisoned mail.
The FBI said there was no connection between blasts at the Boston marathon that killed three people on Monday and mailings sent to Obama, Republican Senator Roger Wicker and an unidentified Mississippi justice official.
Special agents on Wednesday afternoon arrested Paul Kevin Curtis, “the individual believed to be responsible for the mailings of the three letters sent through the US Postal Service”, the bureau said.
The letters “contained a granular substance that preliminarily tested positive for ricin”, it added in a statement.
Earlier reports had said that the letters to Obama and Wicker, which never reached them, were signed “I am KC and I approve this message”.
Curtis was arrested at his home in Corinth, Mississippi, according to the FBI.
