Several students and staff at a Chelsea high school were treated for injuries after a former student broke into the school and sprayed dozens with a fire extinguisher.

According to police, the 24-year-old former student entered Liberty High School on West 18th Street around 1:20 p.m. He approached a school safety agent stationed at the entrance and asked to see a teacher, a request that was apparently denied, as he then allegedly grabbed a nearby fire extinguisher, sprayed the agent, and ran to the school's fifth floor, dousing numerous students along the way.

At least nine students were treated for minor injuries induced by the harsh chemicals, and three school safety agents suffered minor injuries attempting to subdue the man.

The intruder was taken to Bellevue Hospital for psychiatric evaluation, and has not been charged.