PHOTO: CNN
Now playing
02:29
Conservative journalist blames Antifa for rally attack
WASHINGTON, DC - MARCH 05: Sen. John Cornyn (R) (R-TX) talks with Sen. Joe Manchin (D-WV) while walking to the U.S. Senate chamber for a vote March 05, 2021 in Washington, DC. The Senate continues to debate the latest COVID-19 relief bill.  (Photo by Win McNamee/Getty Images)
PHOTO: Win McNamee/Getty Images
WASHINGTON, DC - MARCH 05: Sen. John Cornyn (R) (R-TX) talks with Sen. Joe Manchin (D-WV) while walking to the U.S. Senate chamber for a vote March 05, 2021 in Washington, DC. The Senate continues to debate the latest COVID-19 relief bill. (Photo by Win McNamee/Getty Images)
Now playing
02:54
Axelrod breaks down Manchin's surprising move
sinema
PHOTO: CNN
sinema
Now playing
01:50
Senator's move has many on the internet outraged
PHOTO: FBI
Now playing
02:58
Trump State Department official charged in Capitol riot
WASHINGTON, DC - JANUARY 06: U.S. Sen. Paul Gosar (R-AZ) speaks on the floor of the House Chamber during a joint session of congress on January 06, 2021 in Washington, DC. Congress held a joint session today to ratify President-elect Joe Biden's 306-232 Electoral College win over President Donald Trump. A group of Republican senators said they would reject the Electoral College votes of several states unless Congress appointed a commission to audit the election results. (Photo by Drew Angerer/Getty Images)
PHOTO: Drew Angerer/Getty Images
WASHINGTON, DC - JANUARY 06: U.S. Sen. Paul Gosar (R-AZ) speaks on the floor of the House Chamber during a joint session of congress on January 06, 2021 in Washington, DC. Congress held a joint session today to ratify President-elect Joe Biden's 306-232 Electoral College win over President Donald Trump. A group of Republican senators said they would reject the Electoral College votes of several states unless Congress appointed a commission to audit the election results. (Photo by Drew Angerer/Getty Images)
Now playing
02:19
This is what Rep. Gosar was posting days before Capitol riot
John King Magic Wall 0305
PHOTO: CNN
John King Magic Wall 0305
Now playing
02:17
President Biden sending a team to the US-Mexico border
Senior Advisor to the President Jared Kushner  attends a press conference on September 4, 2020, in the Brady Briefing Room of the White House in Washington, DC. (Photo by Brendan Smialowski / AFP) (Photo by BRENDAN SMIALOWSKI/AFP via Getty Images)
PHOTO: BRENDAN SMIALOWSKI/AFP/AFP via Getty Images
Senior Advisor to the President Jared Kushner attends a press conference on September 4, 2020, in the Brady Briefing Room of the White House in Washington, DC. (Photo by Brendan Smialowski / AFP) (Photo by BRENDAN SMIALOWSKI/AFP via Getty Images)
Now playing
02:50
Jared Kushner disappears from Trump's inner circle
Rep john garamendi 0305
PHOTO: CNN
Rep john garamendi 0305
Now playing
02:33
Rep. Garamendi: Any lawmaker involved in Capitol riots ought to be thrown out of Congress
Protesters gather at Lincoln Park to demand the Emancipation Memorial be taken down on June 23, 2020 in Washington, DC.
PHOTO: Tasos Katopodis/Getty Images
Protesters gather at Lincoln Park to demand the Emancipation Memorial be taken down on June 23, 2020 in Washington, DC.
Now playing
03:01
Why some people want this Abraham Lincoln statue taken down
psaki
PHOTO: CNN
psaki
Now playing
00:56
Psaki fires back at Trump testing czar over vaccine claims
PHOTO: CNN
Now playing
03:04
Avlon: Pence's op-ed is 'way worse than Stockholm syndrome'
PHOTO: CNN
Now playing
01:35
See what security looks like outside US Capitol
PHOTO: Gov. Cuomo's office
Now playing
03:35
Gov. Andrew Cuomo addresses women's allegations
Cuomo
PHOTO: Gov. Cuomo's Office
Cuomo
Now playing
00:56
Cuomo says he has no plans to resign
Now playing
04:51
Elected Republican who supports Biden's bill speaks out
President Joe Biden speaks during a meeting about cancer in the Oval Office of the White House, Wednesday, March 3, 2021, in Washington. (AP Photo/Alex Brandon)
PHOTO: Alex Brandon/AP
President Joe Biden speaks during a meeting about cancer in the Oval Office of the White House, Wednesday, March 3, 2021, in Washington. (AP Photo/Alex Brandon)
Now playing
01:20
'Neanderthal thinking': Biden on states lifting mask restrictions
(CNN) —  

President Donald Trump’s threat to label anti-fascism protest movement Antifa a terrorist organization has prompted a backlash in Germany, where thousands of social media users have pledged solidarity with the group.

Trump tweeted on Saturday that the activist group was made up of “gutless Radical Left Wack Jobs who go around hitting (only non-fighters) people over the heads with baseball bats.” He said a move was being considered to label the movement a “major Organization of Terror (along with MS-13 & others),” referring to the international criminal gang the Mara Salvatrucha.

His tweet followed the introduction of a resolution by Republican Sens. Ted Cruz and Bill Cassidy, aiming to have the group identified as “domestic terrorists.”

But the call prompted a flurry of tweets in the US and in Germany, where #IchBinAntifa – I am Antifa – started trending on Twitter.

Several users who used the hashtag referenced Germany’s history of fascism and anti-fascist resistance during the Nazi period.

“#IchbinAntifa because my grandfather fought the fascists after they nearly wiped out our entire family,” Krsto Lazarević wrote.

Another user added, in a tweet that was retweeted hundreds of times: “#IchbinAntifa Because history teaches us just how fragile democracy and the rule of law are when giving right-wing extremists power.”

German daily newspaper Neues Deutschland added that they were “outraged” that Trump was considering labeling the group terrorists.

Antifa, whose name is short for “anti-fascist,” have become increasingly visible since the Charlottesville protests in 2017, when white nationalists rallied against the removal of a Gen. Robert E. Lee statue, and the Antifa mounted a counter-demonstration that turned violent. Trump infamously said in the aftermath that there were “very fine people” on both sides.

The term is used to define a broad group of people whose political beliefs lean toward the left – often the far left – but do not conform with the Democratic Party platform.

The group doesn’t have an official leader or headquarters, although groups in certain states hold regular meetings.

It is known for causing damage to property during protests, and caused controversy when conservative journalist Andy Ngo claimed he had been attacked by members of the movement.

CNN’s Jessica Suerth and Leah Asmelash contributed reporting.