An 18-year-old male has died and eight other students have been injured after two gunmen opened fire in a school in a suburb of Denver, Colorado.
Two suspects, one adult and one juvenile are in custody, said Douglas County Sheriff’s department.
The school is only about 5 miles (8 km) from Columbine High School – where 13 people were murdered by two students in 1999.
Both suspects are believed to be former students at the Science, Technology, Engineering and Math (STEM) School – in the Highlands Ranch area.
Douglas County Sheriff Tony Spurlock said officers arrived at the school within two minutes of the initial reports of a shooting.
“Two individuals walked into the STEM school, got deep inside the school, and engaged students in two separate locations,” Sheriff Spurlock said.
He said they had both used a handgun in the attacks.
Devon Erickson, 18, has been named as one of the suspects.
As the incident unfolded, students fled from the school buildings. SWAT teams secured the area and snipers took up positions on neighbouring buildings.
Fernando Montoya said his 17-year-old son was shot three times, and that one of his friends was also wounded.
Mr Montoya said his son told him that one of the gunmen walked into his classroom and opened fire.
“He said a guy pulled a pistol out of a guitar case and started to shoot, he told local TV station Denver 7.
Colorado has seen some of the most notorious shootings in recent US history.
The 20-year anniversary of the Columbine massacre was only last month, and in 2012 James Eagan Holmes killed 12 people at a cinema and injured nearly 70 in the Denver suburb of Aurora.
Tuesday’s STEM school shooting also came one week to the day after a gunman opened fire on the Charlotte campus of the University of North Carolina, killing two people and wounding four others.
A 22-year-old former student of the university has been charged with murder and attempted murder.