Capitol Police stand guard outside the Capitol building in Washington on April 16, 2013 as security has been placed on a heightened alert following the bombings at the Boston Marathon. (Getty Images)
WASHINGTON (TheBlaze/AP) -- U.S. Capitol police are investigating the discovery of at least two suspicious packages in Senate office buildings and "the individual who delivered them is being questioned," Sergeant at Arms Terence Gainer said on Wednesday.
Gainer said in an email the packages were delivered to at least two Senate offices.
The development comes on the day after a letter mailed to Sen. Roger Wicker of Mississippi was found in two preliminary tests to contain ricin, a potentially fatal poison. The letter was intercepted at an off-site facility where all mail to the Senate is screened.
It was not clear whether there was a connection between the letter and the envelopes.
Other officials said one of the packages had been discovered in the Russell Building, and the second in the Hart office building.
The Hill's Jeremy Herb tweeted a photo of a Capitol police officer inside the Hart building directing people back into their offices.
Image source: The Hill's Jeremy Herb/ @JHerbTheHill: "Capitol police ordering people on Hart balconies back into offices."
The news broke minutes after the Secret Service said a letter sent to President Barack Obama contained a "suspicious substance" that also tested positive for ricin.
This post has been updated.