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Charge over Obama ricin letter

A martial arts instructor from Mississippi has been charged with attempting to use a biological weapon after ricin-laced letters were sent to Barack Obama and other officials.

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US Senate closes mail facility following poison letter

The US Senate mail facility has been closed for the next two to three days following the receipt of a letter that tested positive for the poison ricin, the Senate Sergeant at Arms told Reuters.

The envelope was postmarked from Memphis, Tennessee, had no return address, and was not "outwardly suspicious" the Senate sergeant said.

The FBI, US Capitol Police, and other agencies are involved in the investigation of mail testing positive for ricin, he added.

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