Four people, including three children aged 5, 8 and 11 and a teacher, were killed in a shooting at Silver Rail Elementary School in Bend, Oregon, on Thursday, while a 7-year-old child and a 54-year-old teacher were critically injured, authorities said.

The 16-year-old suspect, a Bend resident, was also killed after an armed community member pursued him into the school and confronted him, Bend Police Chief Mike Krantz said at a news conference.

The motive for the attack remains unclear, and investigators are examining whether the suspect had any connection to the school or its students.

Police said the first emergency call came at 12:59 p.m. local time from a person who reported being fired at by someone carrying a long gun. The suspect subsequently entered the school by shooting at locked doors, prompting an emergency response.

Officers arrived at the scene at approximately 1:02 p.m. and soon discovered that the suspect had been fatally shot by the community member, according to police.

The identities of the victims and the suspect had not been publicly released as of Friday morning.

The Federal Bureau of Investigation (FBI) is assisting local authorities with the investigation. Officials have not yet announced a motive or established whether the suspect had previously attended the school.

Silver Rail Elementary serves kindergarten through fifth-grade students and has more than 400 pupils. The attack prompted a major emergency response, with authorities evacuating classrooms and establishing a reunification centre at a nearby church where parents could collect their children.

Oregon Governor Tina Kotek expressed sorrow over the deaths and praised the community member who intervened to stop the attack.

She also acknowledged the emotional toll on the individual who confronted the gunman, while expressing support for the victims, their families and the wider community.

Bend-La Pine Schools Superintendent Steven Cook said the district was heartbroken by the tragedy and was prioritising support for students, staff and families affected by the violence.

The school district announced that all schools would be closed on Friday as the community began to cope with the aftermath of the shooting.

The attack has renewed concerns over gun violence in the United States, where shootings at educational institutions have repeatedly raised questions about school security, firearm access and measures to prevent further tragedies.

Silver Rail Elementary is located in Bend, a city of approximately 100,000 people in central Oregon, about 280 kilometres southeast of Portland.

Authorities have urged the public to allow investigators to establish the circumstances surrounding the attack as they continue gathering evidence and examining the suspect's background. (ILKHA)