Bearing flags and crowding onto steps outside Boston City Hall on Saturday afternoon, demonstrators blasted Mayor Martin J. Walsh and Boston police for arresting three dozen people during protests at a Straight Pride event last weekend, demanding that charges against them be dropped.
About 200 demonstrators accused Boston police of racism and violence against protesters who opposed the Straight Pride parade and rally on Aug. 31, and criticized Walsh for allowing Straight Pride organizers to hold the event.
On social media, videos showed police officers using pepper spray on protesters, and several people being tackled by officers and placed into custody.
A Boston police spokesman said four officers were injured that day.
“Drop the charges! Drop the charges!’’ demonstrators chanted Saturday, some holding signs with messages that read “Unite and Fight the Right’’ and “End Police Brutality.’’
Participants in the Straight Pride event, which consisted of a march from Copley Square to a rally at City Hall Plaza, were outnumbered by protesters along the route. The two sides traded chants and barbs, but were kept apart by barricades and a heavy police presence drawing on officers from Boston and other communities.
Event organizer Super Happy Fun America has said heterosexuals are an “oppressed majority,’’ while critics said the group is homophobic and the event was meant to cause anti-LGBTQ discrimination.
Police ultimately arrested 36 people during and after the parade and rally, some for violence against police officers.
During Saturday’s protest — billed as “Shame on Marty Walsh: a response to police violence’’ on Facebook — demonstrators launched into a chant calling for the ouster of President Trump and Vice President Mike Pence before switching to Walsh.
“Marty Walsh must go!’’ demonstrators chanted at one point.
Among the demonstrators at City Hall Saturday was Bambi Snodgrass, a 59-year-old Topsfield resident, who called the police response to the Straight Pride protesters “brutality.’’
She also said she was “extremely disappointed’’ in Walsh over the incident.
“I want Marty Walsh to stand up there and publicly make an apology to these people,’’ Snodgrass said. “I want him to make sure those charges get dropped.’’
Walsh, speaking with reporters during an unrelated event Saturday, repeated previous comments he had made about the need to respect the free speech rights of the Straight Pride organizers and allow their parade.
“I don’t agree with their values, I don’t agree with their issues,’’ Walsh said of the Straight Pride group, later adding, “I think if we found a reason to stop it, it wouldn’t have happened.’’
Walsh also addressed the protesters who criticized him Saturday at the City Hall rally.
“I would love to be able to reach out to say to them, ‘If we could come up with better ways of doing this,’ ’’ he said, referring to the Straight Pride event. “ ‘I would absolutely try and do it a different way.’ ’’
On Saturday, demonstrators called for the resignation of a Boston police captain who they said was responsible for police taking action against the protesters, as they criticized what they said was the militarization of police and law enforcement’s treatment of brown and black communities.
A Boston police spokesman did not respond to requests for comment.
Rachel Bishop, a 28-year-old Jamaica Plain resident, said she attended the rally because she was scared by how police treated protesters at the Straight Pride Parade.
“If they’re willing to use that kind of violence in broad daylight on camera against largely white folks, what are they doing to black and brown people out of sight everyday?’’ she asked.
Demonstrator Chris Legere, 24, of Boston, wanted the rally to raise awareness around “unprovoked police violence against the protesters last weekend.’’
“That’s how change happens and how government is held accountable — by community coming out and making their voices heard,’’ Legere said.
Katherine O’Connor, 16, of Brookline, said she protested at the Straight Pride event and criticized the police response to protesters.
“I am angry, and justifiably so. I’m 16, and should not be seeing this happen. This goes against everything that my parents have taught me about how the state should work,’’ O’Connor said.
John Hilliard can be reached at john.hilliard@globe.com. Sarah Wu can be reached at sarah.wu@globe.com. Follow her on Twitter at @sarah_wu_.