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

Following several Republicans who aired their grievances with a "rushed" process, Rep. Chip Roy, R-Texas, condemned Trump for pressing Vice President Mike Pence to overturn the election but argued he couldn't support the impeachment article as written.

"Let us condemn which must be condemned but do it the right way with deliberation and without disastrous side effects. We must end tearing apart our nation by social media and sound bite," Roy said.

Another Texas Republican, Rep. Jodey Arrington, expressed some discontent at the president's rhetoric but suggested it would set a dangerous precedent to pin the actions of his supporters at the Capitol on the president.

"I'm not saying that the president didn't exercise poor judgment, but to criminalize political speech by blaming lawless acts on the president's rhetoric is wrong and a very dangerous precedent," he said to groans from Democrats. "The criminals who stormed the Capitol that day acted on their own volition. They are responsible. This is an important moment for our nation. We have to come together."

While other Republicans didn't go so far as to directly condemn Trump, they all condemned the violence at the Capitol -- but argued it was time for unity and healing, instead of an impeachment with one week until Biden's inauguration.

Democrats, however, rejected that stance.

"A police officer was killed. And what I hear from the other side is that it's time to heal? He's not even buried yet!" Rep. Donald Norcross, D-N.J., scolded his colleagues.

"If he has four years or four days, we must do the right thing for all Americans because he must be held accountable," he added.

Republicans argued there had been no hearings or witnesses called in the Judiciary Committee, to which Democrats responded that the lawmakers themselves witnessed the violence and immediate action must be taken to avoid further threats.

-ABC News' Benjamin Siegel