A truck ploughed into a female police officer in horrendous scenes caught on camera as protests turned violent in Philadelphia.
Demonstrators gathered outside the 18th District police headquarters at the University of Penn Police on Monday night - hours after officers shot and killed a man that afternoon.
But in the early hours of Tuesday morning tensions rose and rioting broke out across the city.
Police clashed with people protesting the violent killing of 27-year-old Walter Wallace Jr.
In a horrific video released on social media last night, pedestrians were heard screaming after a truck drove towards a line of police officers leaving one injured on the ground.
The silhouette of a person can be seen standing through the sunroof as the truck careers into the officer.
The cop was struck by the vehicle on the corner of S 52nd Street and Walnut Street as a bystander can be heard saying in shock: "Oh my god. He hit a cop."
Philadelphia Police Sergeant Eric Gripp said the officer, a 56-year-old woman, was hospitalised in a stable condition with a broken leg and other injuries.
He added that the truck was found abandoned nearby.
Police said crowds set fire to cars and bins and looted multiple stores late Monday night across the city.
During the protest, at least four other officers were hospitalised after they were struck by bricks, investigators told NBC.
Protests were in response to the shooting of Walter Wallace by two Philadelphia police officers in Cobbs Creek.
Investigators said Wallace was armed with a knife when he approached the officers and ignored them when they told him to drop the weapon.
When he did not put down his knife they shot him, it is claimed.
Video from a witness showed Wallace walking toward the officers as a woman, believed to be his mum, tried to restrain him.
It’s unclear in the video however whether or not Wallace is holding a weapon.
He was taken to a nearby hospital but was later pronounced dead.
Sgt Eric Gripp told the Philadelphia Inquirer that officers ordered Wallace to drop the weapon.
But he added that Wallace "advanced towards the officers" and investigators are reviewing body-worn cameras of what happened.
Wallace’s family have demanded to know why non-lethal force wasn’t used.
He said: "Why didn’t they use a Taser? His mother was trying to diffuse the situation."
The mayor of the city, Jim Kennedy also released a statement last night.
He said: "My prayers are with the family and friends of Walter Wallace.
"I have watched the video of this tragic incident and it presents difficult questions that must be answered.
"I spoke tonight with Mr Wallace’s family, and will continue to reach out to hear their concerns firsthand, and to answer their questions to the extent that I am able."
