Senate received mail that tested positive for ricin, closes mail facility

The U.S. Senate's chief security office said on Tuesday that the Senate's mail facility had received mail that tested positive for ricin and said it was closing the facility for the next two to three days for investigations.

An envelope that had tested positive for ricin had been sent to Republican Senator Roger Wicker of Mississippi, senators told reporters earlier on Tuesday.

The Senate's chief security office did not disclose the recipient's name but said: "The exterior marking on the envelope in this case were not outwardly suspicious, but it was postmarked from Memphis, Tennessee."

The FBI, the Capitol Police and other agencies are involved in the investigation, the Senate Sergeant at Arms said in an email to Senate employees.