The Super Happy Fun America group, founded by three conservative men, kicked off the parade at noon Saturday with controversial right-wing commentator Milo Yiannopoulos serving as grand marshal.
About 150-200 participants marched in the parade, while hundreds of counter-protesters lined the streets on the other side of police barricades.
The parade, led by a Trump 2020 float, traveled a mile and a half from Copley Square to Boston City Hall.
Boston Police said some violent clashes broke out between the two factions, and some arrests were made. Police said details on the arrests would be made available at a later time.
Counter-protesters attending the event reported on Twitter that police were using tear gas to disperse crowds about 4:30 p.m.
The City of Boston granted a permit for the parade in June, explaining the city cannot decline to issue a permit due to a disagreement with a group’s values. The parade received stern criticism from locals including Mayor Marty Walsh.
“It’s not a representation of who we are as a city in Boston,” Walsh told WCVB-TV.
Critics accused the parade’s organizers of being white supremacists intentionally seeking to provoke conflict in the famously liberal city. Parade organizers said they view heterosexuals as becoming an “oppressed majority” in the United States and would like to see an “S” added to the “LGBTQ” initialism to represent straight people.