Two people were killed, including the gunman, and two boys critically injured in a school shooting in the US state of Nevada on Monday, according to officials cited by local media.

Two people were killed, including the gunman, and two boys critically injured in a school shooting in the US state of Nevada on Monday, according to officials cited by local media.

Details of the early morning incident at the Sparks Middle School were not immediately clear, but one witness described for the Reno Gazette Journal how he saw a fellow student shoot a teacher.

The shooting occurred at around 7:15 am (14:15 GMT) Reno deputy police chief Tom Robinson told reporters, adding that the area was now deemed safe.

Two schoolboys taken to Renown Regional Hospital were listed in critical condition, said hospital spokeswoman Angela Rambo, cited by NBC news.

Kyle Nucum, 13, said his teacher saw another student with a gun, and ran to tell him to put it down, but was then shot, according to the Reno Gazette Journal.

Nevada governor Brian Sandoval said on his Twitter feed: "The schools are safe. The rest of the city is safe," adding that his office was receiving regular updates.

A police press conference was scheduled for 11:00 am (1800 GMT).