BEND: A 16-year-old boy shot dead three children and a teacher at an elementary school in the US state of Oregon on Thursday, jolting police into examining how he got hold of the long gun used in his attack.

The latest deadly school shooting in the United States unfolded when the teenager, who has not been publicly identified, shotthroughalockeddoor at Silver Rail Elementary School in central Oregon, according to police.

The teenager killed three children aged five, eight and 11 and one teacher before he himself was shot dead by an armed bystander who had pursued him into the school, police chief Mike Krantz said atapress conference.

Such shootings have become common in the US, with each one reviving debate over gun laws in a country where a right to `keep and bear arms` is protected under the constitution.

Bystander intervenes The bystander was not identified by police, although the New York Times reported that he was the father of two girls who attend the school.

Oregon Governor Tina Kotek said at the press conference that the bystander `heroically intervened to stopfurther loss of life`.Beyond those killed, a seven-year-old student and a 54-year-old teacher were taken to hospital with critical injuries.

It was not clear if the shooter had any prior connection to the school, which has about 450 students from kindergarten through the fifth grade, roughly ages five to 11, and 40 staff members.

The New York Times, citing unnamed law enforcement officials, identified the teenager as John J.

Griffin H, and investigators searched his home and seized electronic devices. They believe he used a 12-gauge pumpaction Maverick 88 shotgun in the attack, which police say is registered to his mother.

Gun law debate Some of the deadliest school attacks in the US include those at Columbine High School in 1999, Sandy Hook Elementary School in 2012, Marjory Stoneman Douglas High School in 2018 and Robb Elementary School in Uvalde, Texas, in 2022.

Advocates for gun-owners` rights have argued for arming teachers as a means of defence. The Gun Owners of America advocacy group pointed to the armed bystander`s intervention in Bend as evidence for their position.-Reuters