Washington, Jan 15 : US President-elect Joe Biden's inauguration rehearsal which was to take place on Sunday has been postponed due to security concerns, according to a news report. In the wake of the deadly January 6 riots staged by supporters of outgoing President Donald Trump at the Capitol building in Washington D.C., the Federal Bureau of Investigation (FBI) has issued a warning about plans of armed protests from January 16 through January 20 at all the 50 state capitols, and from January 17 through January 20, the day of the inauguration, at the Capitol in Washington D.C. The Politico news report published on Thursday night cited two sources as saying that the rehearsal will not take place on Monday (January 18). According to the sources, Biden's team has also cancel'ed an Amtrak trip from Wilmington to Washington planned for Monday "because of heightened security concerns". However, neither the transition team nor the presidential inaugural committee, Secret Service and the Joint Congressional Committee on Inaugural Ceremonies have commented on the development. The Politico news report came a day after the President-elect "received a briefing from senior officials at the FBI, the US Secret Service, and key members of his national security team". On Wednesday, the Secret Service began imposing special security measures for the inauguration, The Hill news website reported. At least 20,000 National Guard troops are expected to be deployed in Washington D.C. The attack on the Capitol building took place on January 6 while Congress was in session considering the ratification of the electoral college votes electing Biden as President and Kamala Harris as Vice President. Five people, including a police officer, were killed during the riots. /IANS