A shooter who killed a student and teacher before turning the gun on herself was a 15-year-old girl who went to the Wisconsin school.

Police said the girl opened fire in a study hall at Abundant Life Christian School, in Madison, on Monday morning (local time).

At least six other people were wounded, according to police. Two students had life-threatening injuries; four other people had injuries that were not life-threatening.

A child in second grade called emergency to report the unfolding nightmare.

When police arrived, they found the teenage suspect with fatal self-inflicted gunshot wounds. The female shooter was identified as Natalie Rupnow, who also went by the name Samantha.

A school shooting carried out by a girl remains a rarity, with only about 3 per cent of all US mass shootings perpetrated by females, studies show.

No officers fired their weapons, police said.

The private Abundant Life Christian School has 400 students from kindergarten through 12th grade.

A family leaves a shelter at the school. Photo: AAP

There was as yet no known motive for the violence, which authorities said took place in one space inside the school. The Rupnow family was cooperating with the investigation, police said.

Madison Police Chief Shon Barnes, a former public school history teacher, said the shooting happened just before 11am on Monday.

“Today is a sad, sad day, not only for Madison, but for our entire country, where yet another police chief is doing a press conference to speak about violence in our community,” Barnes said.

“Every child, every person in that building, is a victim, and will be a victim forever. These types of trauma don’t just go away.”

There have been 322 school shootings this year in the US, according to the K-12 School Shooting Database website. That is the second-highest total of any year since 1966, according to that database – topped only by 2023’s total of 349.

Police responded to a call from a child in grade two. Photo: AAP

In 2022, President Joe Biden signed into law the first major federal gun reform in three decades, about a month after an 18-year-old man opened fire at Robb Elementary School in Uvalde, Texas, killing 19 students and two teachers.

The Wisconsin shooting took place 12 years and two days after one of the most notorious school shootings in US history: The massacre at Sandy Hook Elementary School in Newtown, Connecticut. A 20-year-old man armed with a semiautomatic rifle killed 20 school children ages six and seven, plus six adults who worked at the school.

Polling shows American voters favour stronger background checks on gun buyers, temporary limits on people in crisis and more safety requirements for gun storage at homes with children.

Yet political leaders have largely declined to act, citing the US constitutional protection for gun owners.

-with AAP