Cleveland Transit Cop Pepper Sprays Black Lives Matter Attendees (UPDATE)

The streets of Cleveland turned ugly on Sunday following the first national Black Lives Matter conference, where activists convened to discuss the use of deadly force between police and African-Americans.

Witnesses told local ABC affiliate Newsnet5 that a 14-year-old who was thought to have been intoxicated was slammed to the ground after transit police confronted him about an open container by a bus stop.

The crowd of conference attendees began to protest his arrest by locking arms when a police officer allegedly pepper-sprayed them.

The teenager was seen being taken into an ambulance for treatment and later released to his mother, Newsnet5 reports.

The conference, whose full title is the National Convening of the Movement for Black Lives, began Friday at Cleveland State University. Thousands of activists from across the nation gathered for panels and workshops with the goal of holding officials accountable for police brutality following the deaths of Sandra Bland, Mike Brown, Tamir Rice and Eric Garner.

UPDATE: The Greater Cleveland Regional Transit Police said in a statement issued Sunday evening that the teen was "intoxicated to the point where he was unable to care for himself."

The transit authority said a crowd started to surround the police car in which the teen was held. When the crowd prevented the car from leaving the area, "a Transit Police officer used a general burst of pepper spray in an attempt to push back the crowd, to no avail," the statement said.

The transit police confirmed the teen was eventually released to his mother shortly before 6 p.m. local time.

The incident is under investigation.