CHICAGO (CBS) — Six teenagers have been charged with disorderly conduct, in connection with a series of pepper spray incidents at Morgan Park High School on the South Side.

Six times in nearly two weeks from April 25 through May 7, police and fire crews were called to the school after someone sprayed students with pepper spray. A total of at least 30 students were taken to hospitals, though no one suffered any serious injuries.

On Thursday, police said six teenagers had been charged with misdemeanors in four of those incidents:

• a 17-year-old boy was charged with reckless conduct for the April 25 incident, which sent two people to the hospital;
• two 15-year-old boys were charged with reckless conduct for the April 26 incident, which sent nine people to the hospital;
• a 16-year-old girl and a 17-year-old boy were charged with reckless conduct for the May 2 incident, which sent three people to the hospital;
• and a 17-year-old boy was charged with reckless conduct for the May 7 incident, which sent 11 people to the hospital.

No charges have been filed in the April 30 incident, which sent two people to the hospital, or the May 1 incident, which sent three people to the hospital.

Chicago Public Schools officials said all of the students responsible for the incidents have been identified, and the school has implemented additional school security measures to address the incidents.

“CPS is taking this situation very seriously and we will double down on our efforts until we are confident the situation is fully resolved,” Chicago Public Schools representatives stated in a written statement. “Morgan Park High School is an IB school that provides enriching academic opportunities for its students and our highest priority is ensuring students have a safe learning environment. We will continue ongoing safety and engagement efforts until these incidents come to a stop.”

Many students are sick of it, especially now that all of them are facing extra security measures to get inside the building.

One junior said school officials are checking backpacks every morning.

“That’s not normal at all. We usually just go through the metal detectors and go to our class, but the last week class started getting put 30 minutes behind, because they had to check everybody’s bags,” he said.

Chicago Teachers Union President Jesse Sharkey argues heightened security measures will not do the trick. He said the recently announced cuts to Morgan Park’s teaching staff will only make things worse.

“You really need to have enough staff and personnel in the building with relationships with students,” he said.