Seven injured after shots fired at Denver school

Highlands Ranch, Colorado: Authorities say at least seven people have been injured in a shooting at a suburban Denver school.

Douglas County Undersheriff Holly Nicholson-Kluth said on Tuesday that two suspects had been taken into custody in the shooting at STEM School Highlands Ranch.

She said there was a possible eighth injury and didn't believe there were any other shooters, but tactical teams were still searching room by room.

Nicholson-Kluth didn't know if there were fatalities or other details about the victims or the extent of their injuries.

She said the shooting started in the middle school area and shots were being fired as officers arrived.

Following the shooting, school buses were delivering young children to a recreation centre to be reunited with their parents.

Some children were crying and others held hands with schoolmates as police officers, sheriff's deputies and school administrators helped them off the buses in a light rain.

Eleven buses carrying children pulled up to the centre in a matter of minutes. An ambulance also arrived and dropped off a half-dozen children. None appeared to be physically wounded, but some were crying.

Parents also were streaming into the centre, but no reunions with their children occurred outside in public view.

A man who appeared to be a pastor was walking among small groups of parents, praying with them.

The school is near a sheriff's department substation, and authorities responded quickly.

The shooting occurred at STEM School Highlands Ranch, a public charter school with more than 1850 students in kindergarten through Year 12.

The sheriff's office said deputies responded around 1.50pm local time (5.50am AEST on Wednesday) to the school in the Highlands Ranch community, about 24 kilometres south of Denver.

Lines of firetrucks, ambulances and law enforcement vehicles are at the scene and a medical helicopter landed on a grassy field.

STEM stands for science, technology, engineering and math.