Martin Luther King Jr described a riot as "the language of the unheard" and once again, America's black community finds itself saying the same thing. In Baltimore, violent protests have erupted after the funeral of a 25-year-old man who died from injuries inflicted while in police custody. 

Freddie Gray was arrested by police earlier this month but passed away in hospital last week. After his funeral on Monday, 10,000 people marched peacefully through Baltimore before a small number began rioting across the city, leading to multiple arrests and clashes between police and protesters. In one video, civilians throw rocks at the police – who appear to pick them up and hurl them back:

As shops were looted and buildings damaged, Baltimore police released a statement saying that they had "credible evidence" that rival gangs had met and agreed to "take out" law enforcement officers.  

The mayor of Baltimore has declared a state of emergency, activated the state's reserve of 5,000 National Guard troops and implemented a week-long curfew preventing people from walking the streets at night.

Killer Mike, Rihanna and Le1f have all commented with depressing regularity on America's problem with police brutality over the past twelve months and have done so again in the past twelve hours:

David Simon, author of The Corner and creator of seminal Baltimore show The Wire, pleaded for calm on his blog. "This, now, in the streets, is an affront to that man’s memory and a dimunition of the absolute moral lesson that underlies his unnecessary death," he wrote. "If you can’t seek redress and demand reform without a brick in your hand, you risk losing this moment for all of us in Baltimore.  Turn around. Go home. Please."

Last night's clashes in Baltimore mirror the violent protests that erupted in Ferguson last year following the release of Darren Wilson, the police officer who shot and killed Michael Brown. Freddie Gray joins the alarming list of names which includes Brown, Eric Garner, Walter Scott and Trayvon Martin.

Many believe that these deaths were needless, brutal and unlawful. For now, the city sleeps and calm has been temporarily restored, but there is clearly a sickness within America's justice system. This list of dead men is too long, this scale of protest too large.