Sparks - A shooting at a middle school in Nevada has left two people dead and two boys in critical condition, rattling parents, teachers and students as they showed up for the start of the school week.
The identities of the shooter and victims weren't immediately known. The suspect is "down", police said, and school officials say there is no further danger.
The violence erupted nearly a year after a gunman horrified Americans by opening fire in Sandy Hook Elementary School in Newtown, Connecticut, leaving 26 dead.
The 14 December shooting reignited debate over gun control in general, and how best to protect US schools in particular.
The first reports of the Nevada shooting came in at about 07:15, 15 minutes before the first classes were set to begin.
Students from the middle school and next door elementary school were evacuated to the nearby high school, and classes were cancelled.
The shooting happened on the school's campus, but outside the school building itself, according to police.
Spokesperson Angela Rambo of Renown Regional Medical Centre says two boys are in critical condition.
Governor Brian Sandoval issued a statement after hearing about the shooting.
"I was deeply saddened to learn of the horrific shooting at Sparks Middle School this morning. My administration is receiving regular updates and the Nevada Highway Patrol is assisting at the scene," he said.
Sandoval extended his thoughts and prayers to those affected.
The school, which enrols about 700 students in 7th and 8th grades, has a strict uniform policy that forbids the colours red and blue in students' outfits, colours commonly associated with rival gangs.
Washoe County School District held a session in the spring in light of the Connecticut tragedy to educate parents on what safety measures the district takes.
Sparks, a city of roughly 90 000 that sprung out of the railway industry, lies just east of Reno.