Shocking video footage posted on social media Saturday night shows a Tacoma, Wash., police cruiser plowing into a group of pedestrians.

At least two pedestrians were hospitalized as a result of the incident, the Pierce County Force Investigation Team (PCFIT) told reporters in a late-night news conference, according to KOMO-TV of Seattle. 

The police department has turned the investigation over to the PCFIT. 

One of the patients has been released, KOMO reported. The condition of the patient remaining in the hospital was "unknown" as of midnight PT Sunday. 

Police had responded to the area on reports of drivers street-racing and performing "burnouts" and "doughnuts," attracting spectators, the Tacoma Police Department said in a statement given to Fox News.

About 100 spectators and several vehicles were blocking a downtown intersection, the department said.

When the police cruiser arrived, members of the crowd gathered around the vehicle, hitting it and appearing to threaten police -- prompting the officer to attempt to extricate himself. 

He had used the cruiser's bullhorn to address the swarming crowd, the News Tribune of Tacoma reported. 

"The officer, fearing for his safety, tried to back up but was unable to do so because of the crowd," the statement said, adding the officer's lights and siren were on when he drove forward, with members of the crowd falling to the side or hurrying to get out of the vehicle's path. 

WARNING: GRAPHIC VIDEO

"He was afraid they would break his glass," Tacoma police spokeswoman Wendy Haddow said, according to the News Tribune. 

The officer at the wheel stopped the cruiser when it was safe and called for medical aid, the statement added. 

"I am concerned that our department is experiencing another use-of-deadly-force incident," interim Tacoma Police Chief Mike Ake said in the statement. "I send my thoughts to anyone who was injured in tonight’s event, and am committed to our Department’s full cooperation in the independent investigation and to assess the actions of the department’s response during the incident."

The officer will be placed on leave during the investigation, Tacoma City Manager Elizabeth Pauli told The News Tribune

It was not immediately clear if the officer or any of the pedestrians involved in the reported street-racing would be facing charges -- although video posted by a reporter for the Tacoma News Tribune appeared to show members of the crowd being led away in handcuffs.

A group of protesters gathered at the scene following the incident, according to a Q13 FOX reporter.

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