LOS ANGELES: A shooting at an elementary school in the northwestern state of Oregon on Thursday left "multiple victims", police said, with several media outlets reporting three children and one adult had been killed.
Police said the assailant had been "shot and killed."
"At this time, we have confirmed there are multiple victims," said a statement from local police, who added that at least two people were transported to a local hospital.
"Their status at this time is not known. Children are among the victims," read the police statement.
CNN and CBS News both reported that four people – three children and an adult – were killed, citing law enforcement.
Police had not yet confirmed that information.
Sheila Miller, a spokesperson at the Bend Police department, told journalists that officers were alerted to respond to a critical scene at 1.00pm local time and that police arrived about two minutes later.
"Seconds later, we received word over the radio that the suspect in this incident was down," she said. "At 1:02, as I said, our officers were on the scene, and moments later, the shooter had been shot and killed."
She said they did not yet know who shot the suspect and that it may have been a bystander.
The Bend-La Pine School District said on social media that the Silver Rail Elementary School was under lockdown.
An updated post later said law enforcement was escorting students in buses to a separate location, where families could reunite with their children.
"We are stunned and heartbroken by this senseless tragedy," said Bend-La Pine Schools Superintendent Steven Cook in a statement.
"We extend our deepest sympathy to the families and to everyone affected by this violence. No words can adequately express the grief our community is experiencing."
'Cannot keep accepting this'
The school is approximately 170 miles (270km) southeast of the city of Portland. It serves primary-age students in kindergarten through fifth grade.
The US, where firearms are readily available, is a frequent scene of gun violence, with thousands of people killed every year. It has the highest rate of gun-related deaths among all developed nations.
The deadliest school shooting in US history took place at Virginia Tech on April 16, 2007, when South Korean student Seung-Hui Cho killed 32 people and wounded 17 others before taking his own life.
There have been more than 360 mass shootings in the United States so far this year, according to the Gun Violence Archive, which defines a mass shooting as four or more people shot.
"Our hearts are with the terrified children and the families anxiously waiting to hear that their loved ones are safe," GIFFORDS, a gun safety organisation, said on X.
"We cannot keep accepting this as a fact of life."