Two school administrators were shot at a Denver high school during a confrontation that occurred after a handgun was found on a student subjected to daily searches, authorities said.

The male, juvenile suspect remained at large and the gun was not immediately recovered following the shooting at East High School, Police Chief Ron Thomas said.

The shooting happened just before 10am in an area away from classrooms as the student was undergoing a search as part of a “safety plan” that required him to be patted down daily, officials said.

One of the administrators was critically injured and was undergoing surgery at an area hospital. The second victim was in stable condition, Thomas said. Both victims are male.

Thomas said police know the identity of the suspect and were confident they would apprehend him.

“He obviously is armed and dangerous and willing to use the weapon, as we’ve learned this morning,” Denver Mayor Michael Hancock warned as law enforcement searched for the suspect.

Earlier this month students from the school skipped class and marched to Colorado’s state Capitol to demand stricter gun laws, following the death of a fellow student who was shot while sitting in a car near the school, which has about 2500 students.

There were no school resource officers on campus at the time of Wednesday’s shooting, Thomas said. But following the shooting, Denver Public Schools Superintendent Alex Marrero said two armed officers will be posted at East High School through the end of the school year.

Two administrators were shot at the high school after a handgun was found on a student subjected to daily searches. Photo / AP

In June 2020, amid a summer of protests over racial injustice following the murder of George Floyd, Denver Public Schools became one of the districts around the US that decided to phase out its use of police officers in school buildings. That push was fueled by criticism that school resource officers disproportionately arrested black students, sweeping them into the criminal justice system.

Gun violence at schools has become increasingly common in the US with more than 1300 shootings recorded between 2000 and June 2022, according to researchers from the Naval Postgraduate School and Center for Homeland Defense and Security. Those shootings killed 377 people and wounded 1025, according to a database maintained by the researchers.

Students from East High School had been scheduled to testify Wednesday afternoon before the Colorado Legislature on gun safety bills.

“This is the reality of being young in America: sitting through a shooting and waiting for information just hours before you’re scheduled to testify in support of gun safety bills,” said Gracie Taub, a 16-year-old East High School sophomore and volunteer with Students Demand Action in Colorado.

“Our school experience should not be completely shaped by gun violence.”

The suspect in Wednesday’s shooting had transferred to East High School from another district, Marrero said. Officials did not reveal why the student was being searched daily.

Marrero said safety plans for students are enacted in response to “past educational and also behavioural experiences”, adding that it’s a common practice throughout Colorado’s public schools.

But daily pat downs are rare, said Matthew McClain with the Colorado School Counselor Association, and Franci Crepeau-Hobson, a University of Colorado Denver professor specializing in school violence prevention.

“Clearly they were concerned,” said Crepeau-Hobson. “I can’t imagine they’d do that if there wasn’t a history of the kid carrying a weapon for whatever reason.”

School safety plans are often imposed after students exhibit threatening or suicidal behaviour, said Christine Harms, director of the Colorado School Safety Resource Center. A team that can include counsellors, administrators and police officers assesses the possible threat and develops a safety plan, which can include mental health support, more supervision and searches, she said.

East High School, not far from downtown near a busy street that cuts through the city, was placed on lockdown as police investigated the shooting.

Hundreds of parents lined up along a road near the school, with the scene sealed off by police.

Some parents and students vented frustration over violence at the school as they surrounded the police chief. Others argued about the causes of the violence.

Thomas listened quietly, nodding and promising to engage with the school board.

At the edge of the crowd, a man said the city’s school board members should be recalled for getting rid of police in school, telling a police officer nearby “I just want you to be able to do your job”.

Another man shouted that it was a problem of “evil in the world” while a girl responded that the violence wouldn’t happen if guns weren’t so easily available.

Parent Jess Haase said her daughter, a senior, texted while hiding in a classroom with the lights off during the lockdown. Haase said lockdowns have happened too frequently at the school this year and she was frustrated. She planned to talk to her daughter about taking her out of school for the rest of the school year.

“I am sick of it,” she said.

Denver Public School confirmed the victims were administrators.

A student, right, hugs a man after a school shooting at East High School. Photo / AP

Wednesday was also the second anniversary of 10 people being shot and killed at a supermarket in Boulder, Colorado.

White House press secretary Karine Jean-Pierre said she wasn’t sure whether President Joe Biden had been briefed on the school shooting, but said, “Our hearts go out to the families of the two school administrators in Denver today, and to the entire school community.”

She repeated Biden’s call for stricter gun laws, including bans on assault-style weapons and high-capacity magazines, and for Congress to “do something” on gun control.

- Colleen Slevin, AP