"The White House on lockdown: A federal law enforcement source tells NBC that beginning tomorrow, crews will build a 'non-scalable' fence to secure the WH complex, Ellipse and Lafayette Square," said NBC White House correspondent Geoff Bennett.The network reported that the temporary fence surrounding the White House would be similar to the barrier erected to create a perimeter surrounding the White House, similar to the barrier erected in the aftermath.

The fence will be erected on Monday around the Ellipse and Lafayette Square on 15th Street and Constitution Avenue NW.

A study released in mid-October has warned that five states, Pennsylvania, Georgia, Michigan, Wisconsin and Oregon, are at risk.

In addition to the fence, 250 national guardsmen will be on standby to assist local police.

The White House isn't alone: Businesses from Midtown Manhattan to Portland are boarding up their shops for fear of another wave of unrest.