Arrests expected soon for Trump supporters who stormed the Capitol: Acting attorney general
Supporters of US President Donald Trump inside the US Capitol (AFP)

At least a dozen of President Donald Trump's supporters are expected to be charged in connection with the invasion of the U.S. Capitol as Congress certified Joe Biden's election win.

Acting Attorney General Jeffrey Rosen said federal prosecutors had been working overnight to identify suspects involved in storming the Capitol after a Trump rally outside the White House, and some individuals could be charged as soon as Thursday, reported ABC News.

"Yesterday, our Nation watched in disbelief as a mob breached the Capitol Building and required federal and local law enforcement to help restore order," Rosen said in a statement. "The Department of Justice is committed to ensuring that those responsible for this attack on our Government and the rule of law face the full consequences of their actions under the law,."

Law enforcement officials asked the public for help in identifying suspects seen in photographs and video inside the building, which was locked down after the president's supporters gained access in an apparent effort to stop the congressional certification.

"Some participants in yesterday's violence will be charged today," Rosen said, "and we will continue to methodically assess evidence, charge crimes and make arrests in the coming days and weeks to ensure that those responsible are held accountable under the law."

Four people died during the violent siege, and Rep. Tim Ryan (D-OH) said as many as 60 Capitol police officers were injured, leaving 15 hospitalized and one in critical condition, and many of them were struck by lead pipes.

Ryan, who chairs a subcommittee with jurisdiction over the Capitol, praised individual offices but questioned why police leadership allowed the mob to get so close to the building when they had assured him that could not happen.