The danger to the public and to law enforcement officers from explosive devices during expected upcoming protests "is substantial," the Federal Bureau of Investigation warned in a new awareness bulletin obtained by ABC News on Friday.

The document is full of photos of devices used in the last eight months against civilian and law enforcement targets during public demonstrations.

"Devices targeting infrastructure also increased following violent activity during this time period," the bulletin states.

The FBI now wants to make first responders aware of what has been deployed in the past and what they might encounter during protests linked to the presidential inauguration on Jan. 20.

"The danger posed to law enforcement officers and the general public from the all the tactics listed is substantial," the bulletin states. "If a suspicious item is reasonably believed to contain explosives, an IED, or other hazardous material, DO NOT touch, tamper with, or move the item. Only bomb disposal personal should handle any suspected devices that are located."

An internal FBI bulletin obtained by ABC News earlier this week stated that armed protests are being planned at all 50 state capitols as well as at the U.S. Capitol in Washington, least through Inauguration Day.

The warning comes after suspected pipe bombs were found last week outside both the Democratic National Committee and the Republican National Committee headquarters, just a few blocks from the Capitol where pro-Trump rioters stormed the building.

-ABC News' Aaron Katersky

Biden has chosen Dr. David Kessler, former commissioner of the Food and Drug Administration (FDA), to help lead the federal government's COVID-19 vaccine initiative.

Kessler, a pediatrician and lawyer who headed the FDA from 1999 to 1997 under the Bush and Clinton administrations, will replace Dr. Moncef Slaoui, who is the current chief science officer to Operation Warp Speed.

Biden also announced several other appointees who will join his incoming administration's COVID-19 response team.

"We are in a race against time, and we need a comprehensive strategy to quickly contain this virus," the president-elect said in a statement Thursday. "The individuals announced today will bolster the White House’s COVID-19 Response team and play important roles in carrying out our rescue plan and vaccination program. At a time when American families are facing numerous challenges I know these public servants will do all that is needed to build our nation back better."

With just five days until his inauguration, Biden announced Thursday his pick to head the Federal Emergency Management Agency (FEMA) along with several other key posts for his incoming administration.

Deanne Criswell is his nominee for FEMA administrator. Janet McCabe is his nominee for deputy administrator of the Environmental Protection Agency (EPA). Shalanda Young is his nominee for deputy director of the Office of Management and Budget. Jason Miller is his nominee for deputy director for management at the Office of Management and Budget. And David Cohen is his appointee for deputy director of the Central Intelligence Agency (CIA).

"These dedicated and distinguished leaders will bring the highest level of experience, integrity, and knowledge to bear on behalf of the American people," Biden said in a statement Thursday. "Each of them brings a deep respect for the civil servants who keep our republic running, as well as a keen understanding of how the government can and should work for all Americans. I am confident that they will hit the ground running on day one with determination and bold thinking to make a meaningful difference in people's lives."

Alex Padilla, California’s Secretary of State and the man who will fill Vice President-elect Kamala Harris’ seat in the Senate, told ABC News he’s prepared to balance both the impeachment trial and response to COVID-19 when he’s sworn in next week.

“We have to be able to walk and chew gum at the same time,” Padilla said. “It’s not either or, COVID-19 response is absolutely important. Holding President Trump accountable is extremely important. And doing our part, as the Biden-Harris administration settles, is also extremely important. So we're prepared to do what it takes.”

He said he doesn’t know how the Senate will vote, but believes a “rebalanced leadership” with Democrats in the White House, Senate and House, will give the party “tremendous opportunity” to achieve their goals.

When asked whether he believes last week’s riot at the Capitol would embolden further attacks, he said, “Frankly, when I saw the images last Wednesday, it only emboldened my resolve to want to get to work, and want to get to work quickly.”

-ABC News' Allie Yang

The number of National Guard troops deployed around next week's inauguration could rise from at least 10,000 to 15,000, the National Guard’s top general said Monday.

"Support requests from the Secret Service, Capitol Police and Park Police have been authorized to provide up to 15,000 Guard members to meet current and future support requirements," Gen. Daniel Hokanson, the chief of the National Guard Bureau, told reporters on a phone briefing. "They are troops that have been requested to support security, logistics liaison and communication missions."

Hokanson said that there are currently 6,200 Guardsmen in the District, and there would be 10,000 in place by Saturday.

The National Guard has always participated in inaugurations, and there were 9,000 members on hand last year, but because of the coronavirus pandemic, the number had been reduced to 5,000 for 2021. Last week's insurrection at the Capitol changed those plans, and Pentagon spokesperson Jonathan Hoffman additionally made clear that the Guardsmen will be remaining in Washington after Inauguration Day.

"We're not looking at Jan. 20 as the last day and people will pack up and go home at the conclusion of all the events," he said. "There will be some elements that will remain for a brief period to ensure safety and security in the days following the inauguration as well."

Hokanson, the chief of the National Guard Bureau, said no decision has been made yet about whether to arm the Guardsmen but characterized that possibility as an "ongoing discussion."

"Obviously, we're very concerned that we want our individuals to be have the right to self defense," he said.

-ABC News' Luis Martinez