U.S. security forces probe threats, ramp up to prevent repeat of Capitol mayhem

U.S. National Guard riot shields are laid out at the ready outside the U.S. Capitol Building on Capitol Hill in Washington, U.S., January 13, 2021. REUTERS/Jim Bourg

WASHINGTON (Reuters) - Overwhelmed during the deadly attack on Congress by President Donald Trump's supporters last week, U.S. security forces are mounting a national operation to thwart any violence before President-elect Joe Biden takes office.

Federal and state officials are evaluating online threats and menacing messages to members of Congress and making sure the security operation has the force to repel an attack.