A group of approximately 75protesters were demonstrating peacefully at the Supreme Court, just across the street from the US Capitol, according to a statement from the Capitol Police. As the group was leaving the area, officers began establishing a perimeter of bike racks to keep the protesters away from the Capitol.

“A few people pushed the bike rack down and illegally crossed the police line while running towards the Rotunda Steps,” the Capitol Police said. “Our officers immediately blocked the group and began making arrests.”

Police said, “All will be charged with unlawful demonstration and crossing a police line. Additional charges for some will include assault on a police officer and resisting arrest.”

The protest was organized by two advocacy groups – About Face: Veterans Against the War and Veterans for Peace. The brief sit-in followed a rally and press conference, according to the organizers’ news release.

“We want a future where we invest in care for veterans, in health care, and in education, not where we spend $50 million on a parade,” said Brittany Ramos DeBarros, an Army combat veteran and organizing director of About Face: Veterans Against the War, in a statement.

The arrests come on the eve of one of the largest gatherings expected in Washington, DC, this summer as the Army celebrates its 250th birthday. On Saturday, hundreds of thousands are expected to attend various events around the Capitol as well as the military parade, which is estimated to cost around $45 million and will feature soldiers, tanks, airplanes and other military equipment.

US Secret Service is leading security for the event, which will be maintained by similar fencing the protestors allegedly pushed down near the Capitol on Friday night, but will also be enforced by thousands of officers, 18 miles of anti-scalable fencing, surveillance drones, counter snipers and many other security features.

Special Agent in Charge of the Washington Field Office Matt McCool told CNN the Secret Service and other federal partners are monitoring the protests in Los Angeles and around the country but say they have already planned for the potential of mass protests Saturday.

As of Friday evening, agencies are not monitoring any active threat against the parade and surrounding events.

This story and headline have been updated with additional details.