Three children and a teacher were shot dead by a 16-year-old at a primary school in the US state of Oregon before he was killed by a bystander, police have said.
The suspect, who has not been named, forced his way into Silver Rail Elementary School in the city of Bend on Thursday afternoon by shooting at locked doors.
"We are stunned and heartbroken by this senseless tragedy," Steven Cook, the top administrative official of the local school district, said in a statement.