Looting and violence broke out in California once again during a march Wednesday night in protest of recent police killings of unarmed black men.

Since the weekend, a string of protests have been held in Oakland and Berkeley after it was announced that neither police officer would be indicted in the chokehold death of Eric Garner in New York or the shooting of Michael Brown in Ferguson, Missouri.

On Wednesday, a group of 150 people started a peaceful demonstration at the University of California, Berkeley campus, however it ended in chaos after protesters moved into Oakland and some people began breaking into stores. Protesters also shut down two subway stations in downtown Oakland for some time late on Wednesday, said city officials.

According to police in Oakland, some demonstrators began looting and braking windows. In addition, officials said one person was arrested for assaulting an officer.

At one point, about 50 people broke windows at a T-Mobile store and a Chase bank, said a police statement. Looting also was reported in a downtown area populated with small businesses.

"An officer outside the Oakland Police Department was assaulted and an arrest was made," the statement said, according to Reuters.

A Reuters photographer reported witnessing a plain clothes police officer, who had been participating in the march, pointing his pistol at protesters after he and his partner were attacked. Shortly thereafter, about 20 uniformed officers arrived on the scene to detain one man.

A spokesman for the Oakland Police Department said that it had responded to a request for assistance "made by an outside agency."

On Tuesday, at least 19 people were arrested during protests, including five adults and one juvenile. The California Highway Patrol also apprehended an additional 13, the San Francisco Chronicle reported.