Multiple suspects involved in school shooting in Colorado, US

Officials guide students off a bus and into a recreation centre where they were reunited with their parents after the shooting at STEM School Highlands Ranch. Photo / AP

One victim has died after two gunmen, both believed to be students, opened fire in a Colorado school.

The two males are in custody after officers responded in two minutes to the shooting at STEM School Highlands Ranch, a public charter school with more than 1,850 students in kindergarten through 12th grades.

The school is 12 kilometres away from Columbine High School, where 12 students and one teacher were shot 20 years ago.

Officials guide students off a bus and into a recreation centre where they were reunited with their parents after the shooting at STEM School Highlands Ranch. Photo / AP

Eight people were taken to hospital and Douglas County Sheriff said most are in a critical condition, and one has died.

Douglas County Sheriff said when officers were arriving at the school they could still hear gunshots being fired.

Little kids are coming out in a. Single file line! pic.twitter.com/3Y9oXqiLfr

— Shreya Nallapati (@ShreyaNallapati) May 7, 2019

One student at the school told Fox News that the shooting "was completely out of the blue".

Anxious parents are still waiting to be reunited with their children after the incident.

Parents leave a recreation centre with their child where students were reunited with their parents after the STEM school shooting. Photo / AP

The two gunmen are believed to be students the STEM School Highlands Ranch. Photo / AP

- More to come