This video is difficult to watch and some viewers may find the footage from Berkeley, California disturbing. In it, a line of police in riot gear attempt to surge into a line of peaceful protesters, jabbing with night-sticks. Cries of pain and alarm are heard as the protesters are jabbed in the gut, punched, and knocked to the ground.

In spite of what is apparently a police effort to scatter them, however, the protesters stand firm. They lock arms and chant "Stop beating students!" in unison and the video ends in a tense standoff.

Watch the clip, embedded via YouTube, below: