At least seven students have been injured in a shooting at a school in the Denver area of the US state of Colorado, law enforcement officials said.
Two suspects have been taken into custody.
Deputies from the Douglas County Sheriff's office responded to reports of gunfire at a science and technology school in the community of Highlands Ranch, 40km south of Denver, shortly before 2pm local time today, the sheriff's office said on Twitter.
Seven students, and possibly an eighth, were taken to hospital with injuries, said Douglas County Undersheriff Holly Nicholson-Kluth.
It was unclear whether there were any fatalities, she said in a brief media briefing.
Two suspects were arrested, and law enforcement officers were searching for a possible third suspect, she added.
A man who called into local KOA radio told the station that two people burst into his son's classroom and opened fire, wounding two students.
The father said the victims were alive and that students were able to disarm the gunmen.
At least seven students have been injured in a school shooting in Colorado. @rtenews https://t.co/y8vgwoeI6M
— Brian O'Donovan (@BrianOD_News) May 7, 2019
Colorado Governor Jared Polis said he was sending additional state law enforcement officials to the scene.
"We are making all of our public safety resources available to assist the Douglas County Sheriff's Department in their effort to secure the site and evacuate the students," Mr Polis wrote on Twitter.
We are making all of our public safety resources available to assist the Douglas County Sheriff's Department in their effort to secure the site and evacuate the students. We are monitoring the situation in real time. The heart of all Colorado is with the victims & their families.
— Jared Polis (@GovofCO) May 7, 2019
The violence in Colorado came one week to the day after a 22-year-old gunman opened fire on the Charlotte campus of the University of North Carolina, killing two people and wounding four others before the gunman was disarmed and arrested.
The Colorado school, which combines elementary, middle and high school on one campus has 1,850 students enrolled, according to the district.
There was no immediate information about the ages or identities of the victims or the suspects.
The sheriff's department directed parents to go to a nearby recreation centre to pick up their children.
Local television showed dozens of police and fire vehicles surrounding the school as deputies conducted a room-by-room search of the campus.
The Denver Post reported that all schools in the area where placed on lockdown while police and fire crews responded to the scene.
Some of the worst mass shootings in the United States have occurred in Colorado.
In 1999, two students killed 13 people at Columbine High School in what remains one of the deadliest school shootings in US history.
In 2012, a man opened fire at a movie theatre in Aurora during a screening of a "Batman" film, killing 12 people and injuring scores more.
