A letter sent to the US senate office has tested positive for the poison ricin, reuters has reported.
US senator Durbin said he was briefed by the FBI on an envelope that test positive for ricin.
The senator said he believed the letter was just one of suspicious letters that have been found.
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Regional troops have secured the presidential palace in the Gambia's capital but there are fears the former leader has raided state coffers.
The police officer was shot in the arm at a petrol station on the Crumlin Road, but is in a stable condition.
Temperatures tumbling again tonight with a widespread sharp frost and lows of -5C or -6C and icy spots in places