The Parliamentary Committee to investigate the storming of the US Congress has concluded its first session, and Homeland Security Secretary Alejandro Mallorcas said that domestic terrorism is one of the most deadly threats in the United States today.

The Parliamentary Committee heard the testimony of 4 officers from the Congressional Police regarding their observations of that incident, as the witnesses urged American lawmakers to elevate the committee and its work above political and partisan differences.

Police officer Aquilino Gonel said the attack on Congress - which was carried out by hundreds of supporters of former President Donald Trump - "was like a medieval battle, we fought with hands, inch by inch to prevent the invasion."

"I thought I was going to die," he added, wiping away his tears.

Police officer Michael Fanon, who suffered a heart attack and shocked the head during the attack, said that protesters "arrested and beat him" and "called him a traitor".

He hit the table with his hand while denouncing the "shameful indifference" of some to the shock suffered by the security forces.

Witnesses expressed anger over efforts by some Republican parliamentarians to "stifle or obliterate" the facts, said Representative Liz Cheney, one of the rare figures in the Republican Party to openly criticize Trump.

For his part, the Secretary of Homeland Security said - during a hearing before the Senate Committee on Security and Governmental Affairs - that domestic terrorism is one of the most deadly threats to the United States today.

"That's why we're asking for $131 million to support innovative approaches to preventing domestic terrorism, while respecting privacy and civil rights and civil liberties. This funding will also advance vital research on the root causes of extremism, community outreach and prevention efforts at the local level," Mayorcas added.

For his part, the Republican minority leader in the House of Representatives, Kevin McCarthy, renewed his criticism of the establishment of the Special Investigation Committee, and considered in a press conference that the committee is biased towards Democrats, and aims to settle scores with Trump.

Thousands of Trump supporters stormed Congress on January 6, while the House was holding a session to ratify Joe Biden's victory in the presidential election.