The New York Post first reported the incident, citing anonymous law enforcement sources, but Nathaniel Styer, the deputy press secretary for the New York City Department of Education confirmed the reporting to Newsweek.

Styer told Newsweek that the items were found during scanning across three different schools at the Adams State Campus in Brooklyn. According to Styer, there are at least 1,000 students across all three schools where the metal detector scanning occurred.

“Weapons of any kind have absolutely no place in our schools, and our outstanding School Safety Agents safely recovered these items during screenings, ensuring that all students and staff are safe,” Styer said in a statement sent to Newsweek.

The statement continued, “All protocols were followed, and school staff are following up with students regarding appropriate interventions.”

While speaking with the New York Post, Greg Floyd, president of the school safety agents union, called the discovery of the weapons “the tip of the iceberg.”

“Once again, I ask the question: How many weapons are in our schools? We just don’t know,” Floyd told the New York Post. “This is the tip of the iceberg.”

A spokesperson for the school safety agents union confirmed the number of weapons to Newsweek. The spokesperson also added that several other weapons and contraband items were recovered later in the day on Friday.

According to the New York Post, the 21 weapons found on Thursday included nine knives, four stun guns, seven cans of pepper spray and one pair of brass knuckles.

The spokesperson for the school safety agents union confirmed this reporting to Newsweek and added that on Friday, six stun guns, nine cans of pepper spray and one knife were recovered from metal detector scanning. The spokesperson also said that two bags of marijuana were also confiscated by school officials.

The union spokesperson also explained to Newsweek that only one metal detector was installed in the building, which is home to three different high schools.

The recovery of the weapons comes shortly after a 17-year-old teen was arrested by New York Police Department (NYPD) officers for bringing a loaded handgun and $30,000 into the Urban Assembly School of Law and Justice on Adams Street, which is within the building where the metal detector was installed.

According to the New York Post, after the 17-year-old teen showed up to school late and attempted to enter his attendance, a staff member at the school noticed a handgun in his backpack. School safety agents were alerted of the incident and the teen was eventually arrested.