Rhode Island's attorney general and state police have launched an investigation after protesters accused a prison guard of driving a vehicle into them at an immigration detention centre.
A peaceful protest at an Immigration and Customs Enforcement facility in Rhode Island has ended in chaos after the group was hit by the driver of a truck before being pepper-sprayed by officers.
At least two people were injured, one seriously, on Wednesday night outside the detention facility in Central Falls, according to the Jewish youth movement Never Again Action.
The centre is used by US Immigration and Customs Enforcement, known as ICE.
A video posted by the group on social media shows a black pick-up that protesters claimed was driven by a uniformed corrections officer moving to an entrance blocked by demonstrators.
Protesters surround the truck, yelling and chanting: "The whole world is watching! The whole world is watching!"
Never Again Action said a 64-year-old man suffered a broken leg and internal bleeding and was being evaluated at a hospital for a possible back injury.
It said another person was injured by the truck, and three demonstrators were treated after inhaling pepper spray they say prison personnel used to disperse the crowd.
Democratic Attorney General Peter Neronha said in a statement that it was "unfortunate" and that his office was gathering facts.
The detention centre's warden Daniel Martin said that an employee identified as Captain Thomas Woodworth had been placed on administrative leave as the prison investigates the crash.
Mr Martin said the investigation will examine "correctional officers' response and protocols regarding protest activities outside of the facility."
The prison "supports the First Amendment right of citizens to peacefully protest on public property surrounding the facility," he added.