The FBI said on Wednesday that an investigation into mail containing a suspicious substance addressed to a lawmaker and to President Barack Obama has not found a link to the attack in Boston.
"The investigation into these letters remains ongoing, and more letters may still be received. There is no indication of a connection to the attack in Boston," the FBI said in a statement.
The envelope addressed to Obama was immediately quarantined by the U.S. Secret Service, the FBI said.
Filters at a government mail screening facility preliminarily tested positive for ricin on Wednesday morning and mail from that facility was being tested, the FBI said.
"Only a full analysis performed at an accredited laboratory can determine the presence of a biological agent such as ricin. Those tests are currently being conducted and generally take 24 to 48 hours," the FBI said.
(Reporting by Tabassum Zakaria; Editing by Vicki Allen)
KUALA LUMPUR/PHU QUOC, Vietnam - Malaysia's military has traced what could have been the jetliner missing for almost five days to an area south of the Thai holiday island of Phuket, hundreds of miles from its last known position, the country's air force chief said on Wednesday. | Video
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