Travellers arriving at the airport nearest Washington will face increased security in the run-up to a planned Saturday rally in support of those charged with taking part in the deadly January 6 riot, the Transportation Security Administration said.
“Travellers will notice increased law enforcement and canine presence along with a generally higher level of awareness in TSA’s intelligence-driven, risk-based approach to transportation security,” a TSA representative told Reuters, referring to Reagan National Airport in Virginia across the Potomac River from the capital.
Hundreds of far-right demonstrators are expected in Washington for the “Justice For J6" rally, a reference to the January 6 storming of the US Capitol by supporters of Donald Trump in an attempt to stop certification of President Joe Biden's electoral victory.
On Thursday, the Department of Homeland Security gave warning about the potential for violence at the rally planned for Saturday, a memo shared with state and local authorities and obtained by CNN showed.
One US official who read the warning told Reuters it said department officials lacked “specific credible information” regarding any individual or groups' plans for violence.
The official said the warning appeared to be based on social media postings rather than intelligence gathered from sources inside organisations involved in organising the September 18 events.
Mr Trump has maintained his claims that his defeat was due to widespread election fraud, even after his assertion was rejected by multiple courts, state election authorities and members of his own administration.
The pro-Trump group organising the September 18 rally, Look Ahead America, has alleged that the more than 600 people facing criminal charges over the January 6 riots have been mistreated and singled out because of their political views.
Police have ramped up security around the Capitol in response, mindful of the rioters on January 6 who attacked police, smashed windows and sent members of Congress and former vice president Mike Pence running for safety.
Four people died on January 6, one fatally shot by police and three from medical emergencies. A Capitol Police officer who had been attacked by protesters died the following day. Four officers who took part in defence of the Capitol later died by suicide.
Workers were reassembling a fence that was put up around the white-domed Capitol following that day but it had been taken down in July.
There were few other signs of beefed-up security, though plexiglass police shields could be seen stacked at police checkpoints inside doorways to the Capitol building.
On Wednesday, the US Capitol Police said the Pentagon has been asked to provide National Guard troops if needed.
Mr Trump referred to the coming protest in a statement on Thursday, saying, “Our hearts and minds are with the people being persecuted so unfairly relating to the January 6th protest concerning the rigged presidential election".
Police and congressional leaders said they are prepared for Saturday's protest.
Most members of Congress will be out of town.
House of Representatives Speaker Nancy Pelosi, participating at a forum in Britain on Thursday, said, “They have their plans. Everybody will be more ready for them.”