A shooting at Perry High School in Iowa left three people injured, including two students and the principal, before the shooter turned the gun on themselves.

There were hundreds of emergency services at the scene - which is 25 miles northwest of Des Moines. Ambulances, police units, air ambulances, and firefighters were called to the school at 7.37am. 

The Dallas County Sheriff's Office confirmed the shooting, which happened on the first day of classes. The FBI Omaha Des Moines was on the scene, as was the Bureau of Alcohol, Tobacco, Firearms and Explosive.

County Sherriff Adam Infante confirmed at a press conference at 11am that police officers arrived at the high school seven minutes after the first call was made.

The first responders found 'multiple gunshot victims' inside the school, but Infante said they are still working on confirming the number of victims. He did not confirm if anyone was deceased.

Local news outlet WHO 13 said the shooter, who may be a student, is believed dead from a self-inflicted gun wound.

Adam Infante said that there were few people in the building at the time of the shooting, because the school day had not started yet.

Infante said there is no further threat to the community. They have identified the shooter, but did not confirm if they are alive or deceased. 

The sherriff said: 'The community is safe. We are now working backwards, to see what happened.'