A protest in downtown Brooklyn, New York City, spiralled into mayhem as demonstrators vandalised police cars, banks and burned objects on streets on Tuesday.

A car whose driver's affiliation remains unknown drove through a line of police reportedly injuring one in process. Police officers smashed in car windows before it drove away.

As many as 30 protesters were arrested amid the mayhem.

The protest broke out after 27-year-old Black man Walter Wallace was shot in Philadelphia as officers responded to a report of a person with a weapon in the Cobbs Creek neighbourhood.

Wallace was allegedly armed with a knife. According to the officers, he was shot several times when he advanced towards them.

The man's father said that his son was on medication as he struggled with mental health issues.