VIDEO: Warning graphic content

PROTESTERS have taken to the streets of Chicago after police released a graphic dash-cam video showing an officer shooting 17-year-old Laquan McDonald.

McDonald, a black teenager, was killed in October 2014 by police officer Jason Van Dyke.

Chicago has been preparing for protests in advance of the video's release, which was ordered by a judge, CNN reported.

Van Dyke has been charged with first-degree murder in McDonald's death and is being held without bond.

Soon after the video's release, a group of protesters began marching, chanting "16 shots" and "We got to fight back!"

McDonald died after being shot 16 times.

Cook County State Attorney Anita Alvarez in announcing charges against the officer said:

"It is my determination that this defendant's actions -- of shooting Laquan McDonald when he did not pose an immediate threat of great bodily harm or death, and his subsequent actions of shooting Laquan McDonald while he lay on the ground after previously being struck by gunfire --- were not justified and they were not a proper use of deadly force by this police officer."

Police say McDonald was armed with a 7.6cm (three inch) knife when Van Dyke confronted him. 

The teen did not comply with "numerous police orders to drop the knife," the officer's attorney, Daniel Herbert, told the Chicago Tribune.

The dashcam video released  shows McDonald running, then walking down a road toward several squad cars with flashing lights.

With his left hand near his pocket, McDonald veers away from two police officers, who have their guns drawn.

Seconds later, McDonald appears to spin around, then falls, writhing as shots keep hitting his body, sending puffs of smoke into the air.