The National Guard is lining up in DC and being deployed to many other state capitols including Springfield as federal authorities have new concerns about the extremist threat between now and Joe Biden's swearing in next week.
At the Illinois State Capitol in Springfield Tuesday, board-up crews installed plywood over the windows to protect against possible attackers.
WATCH: Illinois State Capitol boarded up ahead of Inauguration Day
Sangamon County Sheriff Jack Campbell told the I-Team law enforcement is prepared.
"What we're being told by the FBI is that they are monitoring internet chatter, and there's, there's no specific threat. But there's certainly information, floating around out there that concerns us. So we're monitoring that we continue to work together, sharing all the intelligence that we can. And, and make sure that we're prepared for the worst case scenario," he said.
Chaos at the Capitol: Minute-by-minute video shows how riots, violence unfolded
250 Illinois National Guard troopers will be deployed to the Capitol complex and downtown Springfield.
"There is a general threat that, that there will be you know there are flyers that have been put around the internet to have an armed protesters show up at all 50 state capitols... And that's why I want to make sure that we have got the National Guard out there we've got state police local police, as well as federal coordination," said Governor JB Pritzker.
The Michigan National Guard was also activated and the state capitol in Lansing has been boarded up as well. Michigan is among the contested presidential states at most serious risk for a violent armed attack, according to authorities. Illinois not among those.
Steve Georges, a former Chicago Police Deputy Chief, said boarding up windows is not recommended by all law enforcement experts.
"If you're boarding up windows, I would question to make sure that you have some type of barrier or some type of distance in your outer perimeter is far enough to make sure that you don't get those breaches where people could get close enough to do that type of damage," said Georges.
The most significant concern remains Washington, D.C., where President-Elect Joe Biden will be sworn in on Wednesday.
The Pentagon confirmed that 25,000 National Guard members are being put in place there - and that includes several hundred from Illinois.
Currently, the National Guard is not being deployed to Chicago. The head of the city's Office of Emergency Management and Communications said Chicago plans to activate its Emergency Operations Center at OEMC headquarters only on Inauguration Day Wednesday - as of the moment.
"Wednesday is a high profile day for our country. And it's something that we're we're keeping an eye on and realize that it is a high profile. Right we have plans in place we have escalation plans if need be, in any given time whether it's today tomorrow, or through Wednesday, obviously," said Rich Guidice, the Executive Director of OEMC.
With what some extremist groups are calling a "Week of Siege," there are some 51 protests scheduled in D.C., including three expected to be violent, according to federal law enforcement bulletins.
WATCH: Explosive devices pose 'substantial' risk in upcoming protests, FBI says
And in a new alert, the FBI is warning of a specific danger to the public and law enforcement officers from explosive devices during upcoming protests. The FBI calls that risk "substantial."
The national security organization has been circulating photos of the improvised explosive devices that have been seized from radical suspects the past eight months across the U.S., including a type of firework launcher the FBI says is much like one used to torch a Chicago Police vehicle on State Street during rioting last May.
They are devices local law enforcement agencies are now keenly aware of.
"We are always monitoring for something like that. Certainly, our Secretary of State bomb squad and the, the dogs do constantly sweeps of the Capitol and anytime we get any type of intelligence that says anything could happen. We begin those types of sweeps so we're also including that right now in our plan," said Campbell.
The Sangamon County Sheriff, along with Chicago and state officials, said there are no credible threats against any building, person or entity in Illinois. But, the Capital attack last week that started all of this came without a public warning from authorities and law enforcement leaders and experts admits it's what they don't know that has them most concerned.
Along Chicagoland expressways Saturday the FBI was asking for help identifying suspected bad actors who might be plotting some type of violent incidents, somewhere, at some time the next few days.
Suburban Chicago police are having to re-brand the "see something, say something" plea, that for 20 years has applied to potential foreign terrorist threats after 9/11. As the ABC7 I-Team reported, the FBI has now implored local police to ask residents for information on "U.S. Capitol violence" during the siege last week, even if it means snitching on family members.