A Republican congressman on Thursday wrote to the FBI requesting it add Antifa to a list of extremist ideologies under a new category of “Anti-1st Amendment Extremists” -- adding to a growing number of Republicans demanding action against the violent left-wing group.

"Antifa employs violence to coerce Americans into silence,” Rep. Jim Banks, R-Ind, said in a supplementary statement. “As a veteran of the war in Afghanistan, I am intimately familiar with the tactics of terrorist groups and how they employ fear/violence to silence political enemies. To my great surprise, we are witnessing similar style tactics right here in our country. The FBI must take this threat seriously."

TRUMP DECRIES 'GUTLESS' ANTIFA, SAYS HE'S WEIGHING DECLARING GROUP MAJOR TERRORIST ORGANIZATION

Republican calls to deal with Antifa have increased recently after journalist Andy Ngo was assaulted at an Antifa rally in Portland in June. Last month, a 69-year-old man firebombed an Immigration and Customs Enforcement (ICE) detention center before being shot by police. He declared “I am Antifa” in his manifesto, while Banks notes that a Seattle “antifascist” group called him a martyr.

In the letter to FBI Director Christopher Wray, Banks cites instances in which Antifa circulated a list of ICE workers last year, as well as other examples of “criminal and dangerous” activity by the group.

He tells Wray that while the FBI does not keep a public list of domestic terror organizations, it does keep a list of extremist ideologies that can fuel domestic terrorism and suggests the FBI add a new subsection to include Antifa -- called “Anti-1st Amendment Extremists.”

PORTLAND MAYOR SHOULD BE INVESTIGATED BY FEDS OVER ANTIFA ATTACK ON CONSERVATIVE WRITER, SEN. CRUZ SAYS

“Antifa often describes itself as a ‘counter protest’ organization with the stated goal of suppressing fascist speech, political demonstrations and media,” he writes in the letter. “Conveniently, Antifa has redefined fascism to include anyone who disagrees with their opaque political agenda.”

“What that agenda is exactly by design -- their central aim is to silence any and all moderate and conservative politics or ideologies."

CLICK HERE TO GET THE FOX NEWS APP

Banks’ push comes after Sens. Bill Cassidy, R-La., and Ted Cruz, R-Texas, introduced a resolution in the Senate that would designate Antifa as a domestic terrorist organization. President Trump this week backed the push against the group -- whom he described as "gutless radical left wing wack jobs."

"Consideration is being given to declaring ANTIFA, the gutless Radical Left Wack Jobs who go around hitting (only non-fighters) people over the heads with baseball bats, a major Organization of Terror (along with MS-13 & others). Would make it easier for police to do their job!" Trump tweeted.

Fox News' Joshua Nelson contributed to this report.