Police have reopened all the Boston-area highway lanes that were blocked by activists protesting what they call "police and state violence against black people."
State police shut down part of Interstate 93 north-bound south of the city, and I-93 south north of the city at the height of the morning commute Thursday, inconveniencing thousands of drivers.
The southbound lanes were reopened at about 8 a.m. and the northbound lanes at about 10 a.m.
State police say 29 protesters, some of whom chained themselves to concrete-filled barrels, had been arrested.
The Boston contingent of Black Lives Matter said in a statement that the protest was intended "to confront white complacency in the systemic oppression of black people in Boston."
Boston Mayor Martin Walsh called the protest dangerous.