At about 1'25", you can see fireworks start to explode very near to the student onlookers.

On the evening of April 10, students at Hebei Fine Arts Academy in Xinle City, in Hebei Province, said they received messages from their teachers saying that their classes were suspended for the next day but that they should assemble on the campus at 7am, wearing sports clothes. They weren’t given any kind of explanation and at least one media outlet alleged students were told they would be “punished” if they didn’t attend. Some thought that they might be participating in a tree-planting project on the campus, which received worldwide attention for a school building that resembles Hogwarts.Students said that, at 8am the next day, a school counsellor led them to a construction site next to the school, where a clash between school authorities, security personnel and locals was already beginning.The reason for the clashes was land: school authorities purchased the land to develop a theme park, but they had to go to court when locals fought back against the plan, some saying they hadn’t been paid. How a Fine Arts College came to be associated with a theme park is still unclear.On April 5, the judge ruled that the villagers had to clear the land within five days. However, the villagers had 15 days to file an appeal. Eager to start construction, the school ignored this waiting period.When the students arrived, the scene was already chaotic. Three bulldozers and several excavators were at work. The president of the academy was commanding the construction over a walkie-talkie, while dozens of security guards were trying to control protesting villagers. As the students watched, clashes erupted between the security and the locals. Security guards sprayed pepper spray and fire-extinguishers. In response, the villagers threw bricks and set off fireworks. Videos show students chattering excitedly and filming with their phones as things explode.Students told Beijing News that their teachers told them not to get too close to the clashes but encouraged them to “cheer on” the school authorities and construction crew by chanting messages like "this school is our home".Witnesses told the media said that students were not involved in the violent clashes, during which five villagers and ten security personnel were injured. Around 11am, the academy president told students they could leave. He later said he also reported the clashes to local authorities, worried that the situation could get out of hand. Classes resumed in the afternoon.But many students were angry about their strange morning."We come to school to study, but we were asked to be a 'human shield',” one told Beijing News. Others took to social media to post screenshots of the messages that had received from administrators telling them to go to the clashes or to complain.For its part, Hebei Fine Arts Academy denied that students were instructed to participate in the dispute, but that it was investigating the possibility that some staff members had instructed students to participate without the school’s permission. The school said there would be disciplinary measures for those staff members.