A fifteen-year-old teenager opened pyr inside a classroom at school where he attended in Madison, in the upstate Wisconsin of the US, killing two people, a faculty member and another child, and wounding six others before killing himself, police said Monday night (local time; early morning hours today GMT).

A gathering was taking place in the classroom attended by classmates of different grades and teachers, he explained.

The person who opened fire was “identified” as a 15-year-old girl, explained Sean Barnes, the city’s police chief, himself a former teacher.

“She was a student at the school and the evidence suggests she is dead due to a self-inflicted gunshot wound,” he added.

The teenager used a handgun.

The new mass shooting – gun attacks involving four or more victims, in the terminology of US law enforcement – inside a school was committed at Abundant Life Christian School, a private school in Madison, the Wisconsin state capital of about 270,000 people.

Among the injured, two children are in serious condition and are considered to be in life-threatening danger, while another faculty member and three children are in less serious condition.

The commission of such an attack in a school by a girl remains an extremely rare occurrence in the US, after all, only 3% of mass shootings in the US are committed by women or girls, according to studies.

The motive is not yet known. The parents of the teenager are cooperating fully with authorities and police do not plan to charge them, according to Mr. Barnes.

“Today is a very sad day not only for Madison, but for our entire country as another police chief holds a press conference to talk about violence in our communities,” Barnes said earlier in the day. “Every child, every person in this building is a victim and will remain a victim for the rest of their lives. Such wounds do not heal,” he added. He pointed out that 911 received a call from a second-grade student to say that a gun attack had been committed at his school – urging reporters to realize what he had just said.

There have been 322 recorded gun attacks inside a school in the U.S. this year, according to data from the specialized website K-12 School Shooting Database.