The National Guard has been told to be on the lookout for improvised explosive devices after the Defense Department received a credible threat assessment Wednesday that armed protesters are planning to disrupt events surrounding the inauguration of President-elect Joe Biden. 

WASHINGTON'S SECURITY PREPS IN HIGH GEAR FOR INAUGURATION

Members of the National Guard assemble on Capitol Hill on Jan. 12. Photo Credit: Chris Kleponis/Sipa USA

Officials increased the number of National Guard members who will be deployed in Washington during the presidential inauguration from 15,000 to 20,000 on Wednesday, more than three times the number of U.S. troops currently deployed to Iraq and Afghanistan combined.

Wednesday's security briefing prep is the same one that troops receive before being deployed for Baghdad or Kabul, a senior defense official who is part of planning the security measures for the event told Fox News. Most of the National Guard will be armed with standard-issue M4 rifles.

The inauguration comes exactly two weeks after insurrectionists stormed the Capitol while lawmakers held a joint session to certify the Electoral College votes for Biden in the presidential election. Five people, including a U.S. Capitol Police officer, died in the unprecedented attack on Jan. 6.

VIRGINIA NATIONAL GUARD ACCEPTING DONATIONS, CARE PACKAGES FOR TROOPS IN WASHINGTON, DC

National Guardsmen are seen Wednesday, Jan. 13, 2021, on a fence erected to reinforce security at the Capitol in Washington. (AP Photo/Shafkat Anowar)

On that same day, the Washington, D.C., bomb squad responded to reports that multiple IEDs, resembling pipe bombs, were found near the headquarters for both the Republican National Committee and Democratic National Committee. No arrests have been made in connection with the incident. 

The FBI said agents are on heightened alert ahead of Inauguration Day as well, warning that armed groups have planned to stage a "huge uprising" to protest Biden's presidency. 

Platoons of National Guard members have been patrolling outside the newly fenced perimeter of the Capitol a week ahead of the events, with hundreds of troops spread out across the Capitol lawn, many with duffel bags awaiting instruction.

Hundreds of National Guard troops gather inside the Capitol to reinforce security on Wednesday, Jan. 13, 2021, as the House voted to impeach President Trump for inciting a mob that stormed the building last week. (AP Photo/J. Scott Applewhite)

Public access to the inauguration, which was already scaled back as a result of the coronavirus pandemic, will be further limited. City officials are erecting a perimeter throughout downtown, putting up barriers around the White House, the National Mall and the Capitol. In order to travel through the perimeter, people will need to provide proof of essential purpose.

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Fox News was told that Interior Secretary David Bernhardt, a Trump appointee, has not yet agreed to cancel protests scheduled from now until the inauguration despite a request from D.C. Mayor Muriel Bowser, who has extended the number of days that the inauguration will be considered a national security event.

Fox News' Megan Henney contributed to this report.