Sixty-five people were arrested on Saturday after participants in a march against police brutality blocked Interstate 83 just north of downtown Baltimore.
The arrests created a chaotic scene around Penn Station, where thousands milled around for the annual Baltimore Artscape festival.
The march, which was named and tagged on social media as "Afromation," began at Guilford Avenue and Chase Street, moved through Artscape on Charles Street, then to St. Paul Street and past Penn Station to the I-83 onramp, which was closed for the festival.
"Once on the interstate, they locked arms and blocked traffic along the northbound lanes for a short period of time before officers arrived and began making arrests," Baltimore police spokesman Lt. Jarron Jackson said in an email.
Fifty-five adults and 10 juveniles were arrested. Police said those arrested will be charged with failure to obey and illegally walking on a highway.
Processing was still continuing at midnight, police said.
David Blair, one of the organizers of the march, said the group blocked the interstate for about two or three minutes until a group of police officers told demonstrators they needed to unblock the expressway to allow an ambulance through.
"We complied with the officers," said Blair, 21, who was not arrested. "I think there are so many people that deserve to get arrested — not peaceful protesters."
Blair said the group moved to the shoulders of the expressway. But instead of an ambulance, two police vans drove through and parked on the shoulder, and more police officers came out of them. The officers told the group they needed to leave the area, and Blair said they complied.
Those officers followed and corralled the protesters as a group of officers marched down the onramp, Blair said.
Protesters were then arrested and led into Penn Station or to police vans waiting at the station. A large crowd of Artscape spectators and activists circled around and chanted their support for those arrested.
No one resisted arrest, Blair said. Police did not use any visible force, though Blair said a couple of protesters were forced onto their knees.
Police did not immediately respond to questions about tactics used to arrest protesters.
Those arrested were taken to Baltimore police's Northern District station, Blair said. Police said they will be processed at Central Booking.
Blair, a University of Baltimore student and co-leader of New Lens Productions, a self-described youth-driven "social justice organization" of filmmakers, said the group's demonstration was asserting that "black lives do have validation in this country."
He said the group marched peacefully to raise awareness for many issues, including the underfunding of schools and services in African-American and minority neighborhoods, as well as the treatment of African-Americans by law enforcement.
Karen DeCamp, the mother of 17-year-old David Pontious, a 2016 City College High School graduate who is attending the University of Maryland, College Park, to study government and politics, said her son was one of those arrested.
"Love that kid's integrity," she said.
"I'm proud that my son is standing with the Black Lives Matter movement," DeCamp said. "They have specific demands that our city leaders need to look at and act on including the civilian review board and rebalancing the funds going to police versus [toward] youth, community services."
Morgan State University professor Lawrence Brown, who marched with demonstrators, said he didn't understand how police could legally arrest some protesters who didn't make it to the expressway and were just on the closed onramp.
"I know the folks who definitely shouldn't have been arrested were people who didn't make it off the ramp," he said.
Baltimore Sun reporter Kevin Rector contributed to this article.