Police in Boston said at least 40 people had been arrested by 3:00am Monday (local time) after Sunday afternoon’s protest got violent.
The protest was mostly peaceful in the afternoon, but protesters clashed with officers after nightfall.
There were reports of people throwing rocks, breaking into several stores and lighting a police vehicle on fire. Boston Police tweeted that some were throwing glass bottles at officers.
Police said seven officers had been hospitalized and 21 police vehicles were damaged.