A transit police officer has been filmed pepper-spraying a crowd protesting the arrest of a teenager at a Black Lives Matter conference in Cleveland on Sunday.

The incident took place near Cleveland State University where the city’s first ever Black Lives Matter conference was taking place. It was attended by more than one thousand people discussing a range of social issues.

According to the Greater Cleveland regional transit authority, officers were escorting an intoxicated teenager to a police station before a large crowd blocked their path to the police car, as seen in the video below.

They got a 14 year old handcuffed going into the ems #m4bl pic.twitter.com/q42VeGcgYN — #PennyRaps Dropped. (@RicWilson) July 26, 2015

Here are some of the injuries caused by the pepper-spraying.

A video posted by Andrew Humphrey (@humphreymarion) on Jul 26, 2015 at 2:07pm PDT

The teenager was released after a medical examination at 6pm with the crowd reacting in jubilant scenes and chants of “I believe that we will win.”

They just let the teenager go. "This is what community looks like." #M4BL pic.twitter.com/bqhA8N9v9m — Mvmt 4 Black Lives (@mvmt4bl) July 26, 2015

No arrests were made; and the officer’s name has not been released. As a member of the transit authority, the officer is not affiliated with the city’s police department.

Activism against police brutality is growing in Cleveland after the cases of Tamir Rice, Tanisha Anderson and Timothy Russell and Malissa Williams. The latter is the most high profile case in Cleveland.