'Non-scalable' fence erected around Capitol building ahead of Biden's inauguration

A "non-scalable" seven-foot fence is being erected around the US Capitol ahead of Joe Biden's inauguration as officials admitted "catastrophic" security failures had allowed rioters to breach the halls of Congress.

The scenes of an angry mob swarming through the Capitol building on Wednesday alarmed security officials, who fear protesters may have become emboldened by the feeble security which enabled hundreds to surge through the seat of government.

Security measures for the president-elect's swearing in ceremony, which will take place outside Congress on January 20, are being revised accordingly.

Muriel Bowser, the Democrat mayor of Washington, announced on Thursday that the seven-foot, non-scalable fencing would surround the Capitol for at least the next 30 days.

The Pentagon has authorised more than 6,000 National Guard troops from the District of Columbia and neighbouring states to be deployed in the city by this weekend.

The US Secret Service, which is responsible for Mr Biden's protection, is also reassessing its security plans for the day, according to the Washington Post.

“There’s going to have to be major, major reviews of what happened and changes made,” Amy Klobuchar, a Democrat senator involved in the planning of Mr Biden’s inauguration, told CBS News.

Mrs Klobuchar criticised the lapses which allowed a mob to breach the Capitol building's perimeter, saying there must be a "beefing up" of security before the inauguration.

The Minnesota senator questioned how security officials were not prepared for the events that unfolded on Wednesday.

"They knew on social media that the president had been whipping them up. They knew it," she said.

The city's mayor, Ms Bowser, pointed the finger of blame for the "catastrophic failures" at the Capitol Police, a 2,000-member force under the control of Congress.

She said: "Obviously it was a failure or you would not have had people enter the Capitol by breaking windows and terrorising the members of Congress who were doing a very sacred requirement of their jobs."

Ms Bowser warned said she may have to take "extraordinary measures" to maintain public safety in the coming weeks including further curfews.

The Democrat mayor also called for Washington DC to become a state and transfer to help it protect the Capitol. At present, command of the district's National Guard troops rests with the president.

The mayor also called on Congress to set up a nonpartisan commission to look into the security failings. "What happened is textbook terrorism," she said.

Law enforcement officials' treatment of the rioters has drawn comparisons with the Black Lives Matter protests that rocked US cities throughout the last year.

"When Black people protest for our lives, we are all too often met by National Guard troops or police equipped with assault rifles, shields, tear gas and battle helmets," the Black Lives Matter Global Network Foundation said in a statement.

"When white people attempt a coup, they are met by an underwhelming number of law enforcement personnel who act powerless to intervene, going so far as to pose for selfies with terrorists."

Cori Bush, a newly-elected congresswoman who was assaulted by police during a 2014 protest in Missouri, said the race of the Capitol rioters was a significant factor in their ability to breach the perimeter. Had the majority of the mob been black, she said, it "would have been laid out".

It came as the FBI sought the public's help in identifying the hundreds of people involved in the siege of the Capitol and vowed to hold them accountable.

The agency asked the public to share information, pictures or footage of the incident to help them identify the perpetrators.

The FBI is taking the lead on an investigation into two pipe bombs that were recovered from the headquarters of the Republican and Democratic national committees.

At least 60 men and eight women had been arrested as of Thursday evening and were expected in court later that day.

Most face initial charges of violating the 6pm curfew imposed to quell the unrest. Several others were arrested on charges related to carrying unlicensed or prohibited firearms.

The Capitol Police said they had arrested another 14 suspects in connection with the rioting, most charged with unlawful entry.

The Justice Department announced it would also consider federal sedition charges - a policy adopted in the summer for anti-racism protesters - to those who stormed the Capitol, smashed windows and stole property.