The U.S. Capitol is blocked again and the rehearsal for Biden's inauguration has been suspended.

Security issues remain a concern on the eve of Biden's inauguration. On Monday, the U.S. Capitol Police Department said in a statement that after an external security threat occurred near the Capitol, the acting director ordered the blockade of the building out of cautious consideration. and advised employees to take refuge on the spot.

The US Secret Service said in a tweet that a small fire broke out near the US Capitol and that the building was cordoned off and the public would not be threatened out of caution.

According to witnesses, Biden's inauguration rehearsals have been suspended and all rehearsals have been moved to the Capitol. Biden will be inaugurated as president of the United States on January 20.

But the final investigation showed that it was only a "false alarm". Later in the day, the police of the US Capitol said that the small fire was caused by a fire started by homeless people, which had eliminated the danger and lifted the blockade of the Capitol.

Security issues have become increasingly important since Trump supporters "captured" the Capitol on Jan. 6, and all parts of the United States are wary of possible violent protests. After Vice President Pence confirmed that Biden won the US election, some Trump supporters even called for Pence to die.

At a special time when Biden is about to take office, four US state attorneys general and three senators wrote to Facebook, on Friday demanding that arms advertisements be stopped to prevent further violence related to the presidential transition. Facebook then announced on Saturday that it would ban advertisements for weapons, ammunition and silencers, as well as accessories such as gun safes, special vests and holsters in the United States, which will last until at least Friday.