A GUNMAN has opened fire on a school in Denver, Colorado, injuring at least three people on Thanksgiving Day.
Police stormed Manual High School on Thursday afternoon to reports of gunfire.
Officials say three people have been injured, with one young boy shot in the arm, a woman shot in the leg and the third person, a boy "sustained multiple gunshot wounds".
John White, Denver Police Department spokesman, told the Denver Channel: "All three are currently undergoing treatment at area hospitals."
A woman and two boys have been rushed to hospital.
The female victim is said to have alerted police after she was shot.
It is unknown if the injuries are life-threatening.
Police said they belive two or three suspects are involved and one is described as wearing a green and white shirt, while the another was wearing white hoodie.
They fled on foot and remain on the loose.
Denver police department tweeted: "#DPD Officers are in the 1700 block of E. 28th Ave investigating a shooting. 3 victims transported to the hospital. No suspect information available at this time."
It is unclear who was in the school at the time as students had the day off.
Americans are celebrating Thanksgiving and public schools are closed for the holiday.
Information about the shooter has not yet emerged, but police said there is no immediate threat to the public.
An investigation is underway and police are interviewing a number of people at the scene.