Several people were injured amid mass chaos at a Baltimore Pride event Saturday when a “chemical agent” was released into a crowd near a music stage, cops told The Baltimore Sun. It remains unclear who was behind the incident or what the chemical was, though police said it might have been mace, hair spray or “another agent,” the newspaper reported. Around the same time, fireworks were set off near the crowd, leading many to flee the scene—causing the chaos that led to many of the injuries reported. “Our officers are diligently reviewing the surveillance video to gather all the necessary information and determine the sequence of events,” a Baltimore Police spokesperson told The Sun. The event was temporarily shut down following the incident while authorities assessed the scene and treated those who had been injured.