(CNN) -- A staff member was killed and two students were injured after a student opened fire at a Nevada middle school on Monday, police said.
The "student/suspect" in the case was also killed, Washoe County School District Police Chief Mike Mieras said.
Authorities said it was too soon to say whether the suspected shooter was killed by a self-inflicted wound or a law enforcement shot.
The motive in Monday's shooting was unclear.
"As you can imagine, the best description is chaos," said Tom Robinson, deputy chief of the Reno Police Department. "It's too early to say whether he was targeting specific people or just going on an indiscriminate shooting spree."
A 13-year-old student told the Reno Gazette-Journal that he saw a student fire a shot at a teacher.
"The student was pointing a gun at the teacher after the teacher told him to put it down, and the student fired a shot at the teacher, and the teacher fell, and everybody ran away," the student said.
One of the injured students underwent surgery, Mieras said, and the other is "doing well."
Authorities released few details about the incident, but city officials said in a statement that the suspect was "neutralized."
"Law enforcement assures that the school and community are secured at this time," the statement said.
City officials said authorities received emergency calls from students and staff at the school about 7:15 a.m. about an active shooter on campus.
Authorities said students were being taken to a nearby high school to meet their parents. School was canceled for the day at Sparks Middle School and nearby Agnes Risley Elementary, officials said.
"I was deeply saddened to learn of the horrific shooting at Sparks Middle School this morning," Nevada Gov. Brian Sandoval said in a statement. "My administration is receiving regular updates and the Nevada Highway Patrol is assisting at the scene. Kathleen and I extend our thoughts and prayers to the victims and those affected by these tragic events."
The shooting comes months after a gunman killed 26 people at Sandy Hook Elementary School in Newtown, Connecticut, igniting nationwide debate over gun violence and school safety.
The mother of a student killed in December's shooting in Newtown said Monday's shooting was reminder of the need to find solutions to keep students safe.
"The unthinkable has happened yet again, this time in Sparks, Nevada," Nicole Hockley said in a statement. "Our thoughts and prayers are with the victims, their families, and the children of Sparks Middle School, who today came face to face with violence that no child should ever experience. It's moments like this that demand that we unite as parents to find common sense solutions that keep our children -- all children -- safe, and prevent these tragedies from happening again and again."
CNN's Jason Hanna and Karan Olson contributed to this report.