At least seven people have been injured following a school shooting in the United States.
The incident happened at Highlands Ranch school near Denver, Colorado, this afternoon at around 1.53pm.
The school was placed on lockdown following reports of several active shooters on the loose at the location.
At least two people have been detained by police while a third person is being held under investigation.
But further details about the attackers have been revealed by police
A police spokesperson said they are clearing the school 'room by room'.
“This is still an active shooter situation. We still don’t know whether there is still an active shooter inside,” said a spokeswoman with the Douglas County Sheriff’s Office.
Elementary school children were seen filing out of the school with their hands in the air.
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At least two people have taken to hospital while paramedics treat others at the scene.
Witnesses say one victim was carried out over the shoulder of a policeman, while another was taken out in a stretcher.
"A high ranking law enforcement source says "multiple" victims have been shot at a school in suburban Denver", ABC reporter Clayton Sandell said.
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"Two suspects are in custody. Police are 'engaging' a third."
Douglas County Sheriff's Office tweeted: “Unstable situation, shots fired at STEM school at Ridgeline and Plaza.”
"STEM school incident: still getting info, believe 2 injured. Please find other routes. Media staging now on south side of AMC”.
The school is located approximately 8 miles from Columbine High School - the scene of a notorious school shooting that claim the lives of 24 people.
According to the website for STEM (Science, Technology, Economics and Mathematics)School Highlands Ranch is an “innovative, free, public, charter learning community.”
It serves children from kindergarten to final year 12th grade students aged from 17 to 18.
Officers have advised people to stay clear of the area and other schools in the area have also been placed on high alert following the incident.
We'll be bringing you the very latest updates, pictures and video on this breaking news story.
