NEW YORK -- Demonstrators in New York clogged the Brooklyn Bridge in a mass protest against incidents of police violence across the country.
CBS New York reported a large group of people began marching in Lower Manhattan toward the bridge, eventually blocking the roadway and halting traffic.
The demonstrations were part of a national day of action to call for the end of police killings of unarmed people. Many of the cases involve white police officers and black or Hispanic victims.
The group, which was at one point 400 strong had dissipated to about 50 by the time it crossed the span.
At least three dozen people were arrested.
At one point, police say, an off-duty police officer driving home across the bridge was assaulted by two protesters when he got out of his vehicle, and the suspects ran off after he identified himself as a police officer. The march was organized by National Actions to Stop Murder By Police. Several people were seen being taken into custody. New York Mayor Bill de Blasio condemned the violence.
Meanwhile, protesters in California staged similar rallies in Oakland and San Francisco. Hundreds gathered in front of city halls in both cities chanting slogans and engaging with policymakers on solutions to the discord with law enforcement.
Protesters then briefly shut down the city supervisors' 2 p.m. weekly meeting, chanting "no justice, no peace, no racist police," CBS San Francisco reported.
In Madison, Wis., high school students blocked the street to protest the death of an unarmed biracial man at the hands of a white police officer last month. Police declared the gathering an unlawful assembly and ordered protesters to leave the street. At least one person was arrested.
Last year massive protests took place in cities nationwide after grand juries declined to indict officers in the cases of Mike Brown in Ferguson, Mo., and Eric Garner in New York. But cases like the police shooting death of Walter Scott in North Charleston, S.C., and Eric Harris in Tulsa, Okla., have touched off the latest demonstrations.