The national co-convenor for Students for Palestine Jasmine Duff said the police were to blame for the violence, Al Jazeera reports.

“They used serious weapons on peace activists that should be banned for use on demonstrators, including pepper spray, which is classified as a chemical weapon,” Duff said in a statement, according to the AP news agency.

“They hit us with batons, including hitting one man so hard he had to go to hospital and they shot us with rubber bullets,” she added.

The organiser of the convention, AMDA Foundation, said it would not comment on protester activity.