People gather at City Hall to protest vaccine mandates on August 9, 2021, in New York City.
CNN  — 

Law enforcement officials and businesses in the nation’s capital are preparing for an influx of anti-vaccine mandate activists and are also concerned that potentially large-scale demonstrations could attract extremist groups to the region this weekend.

Ahead of the weekend, there has been extensive planning and information among the Federal Bureau of Investigation, Department of Homeland Security, Metropolitan Police Department, US Park Police and others, a federal law enforcement official told CNN.

Metropolitan Police held a conference call with businesses leaders​ and assured them there will be a visible law enforcement presence prepared to make arrests for unlawful entry if patrons refuse to leave a private business, according to a source familiar with security plans in Washington.

The protests coincide with new proof-of-vaccine requirements for restaurants, bars, gyms and other private businesses in DC.

US Capitol Police, with assistance from the Montgomery County (Md.) Police Department, is moving to all-hands-on-deck staffing this weekend, according to sources familiar with the planning. The agency declined to provide specific details of its security plan.

“I am confident in our preparation for this weekend,” US Capitol Police Chief Tom Manger told CNN in a statement. He said the agency is keeping a “close eye” in particular on the “Defeat the Mandates: An American Homecoming” event planned for Sunday on the National Mall.

The protest is intended to bring together those who oppose vaccine mandates and passports, Covid-19 vaccines for children and other coronavirus requirements.

The permit on file with the National Park Service says the event could draw up to 20,000 people. It begins Sunday morning at the Washington Monument and ends at the Lincoln Memorial that afternoon. Speakers include Robert Kennedy Jr. and former “60 Minutes” correspondent Lara Logan, according to the event’s website.

Also on Saturday, protesters from “Refuse Fascism” plan to rally outside the Supreme Court to call for abortion rights. Separately, the National Pro-Life Summit in Washington on Saturday will feature former Vice President Mike Pence, who has repeatedly called for reversing Roe v. Wade.

The weekend protests follow Friday’s March for Life, during which about 30 men who appeared to be tied to Patriot Front, an American nationalist White supremacist group, showed up, attracting a significant police presence.

Rank-and-file Capitol Police officers were put on notice of potential violence this weekend and that the White House is a potential target for protesters, according to a source familiar with the communication.

DHS does not have information “indicating any specific, credible threats related to the events occurring tomorrow and this weekend in the national capital region,” a department spokesperson told CNN.

However, “the United States is in a period of heightened threat,” the spokesperson added, pointing out that domestic violent extremists and those inspired or motivated by foreign terrorists or other malign foreign influences continue to pose a threat.

And officials are concerned because the events center on issues that are the focus of disinformation campaigns from both foreign and domestic threat actors, according to the federal law enforcement official.

Although there have not been credible, specific calls for violence related to the protests, there has been a mix of online chatter related to the weekend, ranging from commentary about the perceived ineffectiveness of nonviolent events to speculation that protests are a law enforcement trap to arrest people who attend. There is also the possibility of clashes with counterprotesters, the official said.

“The objective is to make sure that those who are coming to the District to engage in constitutionally protected events can do so in a safe manner,” the official said.

In response to CNN’s inquiry about the possibility that the “Defeat the Mandates” march will bring extremists or hate groups, Rita Shreffler, director of media relations for Children’s Health Defense, which is planning the event, said in an email that they are committed to nonviolent resistance and that vaccine mandates are a form of “government sponsored violence.”

Organizers of “Defeat the Mandates” tell CNN they are adding security to ensure a peaceful event. They have “contracted out comprehensive private security who will work in concert with local and federal law enforcement in keeping this March peaceful,” Louisa Clary, the director of the march, told CNN.

Extremism researchers point out the “Defeat the Mandates” event and a similar two-day event this weekend called the “World Wide Rally for Freedom” are gaining attention due to cross-promotion.

“The most noteworthy development is that the two major anti-vaccine events planned for this weekend are now officially linked,” Rita Katz, executive director of SITE Intelligence Group, said in a statement.

“This has increased the visibility of both campaigns. It is also certain that MAGA/Stop the Steal supporters will also participate in the D.C. event, given that it has been endorsed and promoted by Steve Bannon,” Katz said.

“Although we have not yet seen the events being discussed by organized violent extremist groups such as the Proud Boys, the scale of promotion suggests significant participation, and it cannot be ruled out that provocateurs and accelerationists will join.”