Two children have been seriously wounded after a classmate opened fire at a middle school in Roswell, New Mexico. The shooter, 12 years old, was armed with a shotgun. The victims were an 11-year-old boy in critical condition and a 12-year-old girl in serious condition. New Mexico Gov. Susana Martinez briefed reporters on the attack.

Gov. Susana Martinez: “Student from Berrendo Middle School walked into the school this morning, and while students were gathered in the gym because of the weather — they gather in the gym to stay out of the cold weather — this individual opened fire on the audience that was in the gym. The shooter was quickly stopped by one staff member who walked right up to him and asked him to set down the firearm, which he did. He was also assisted by a state lieutenant, state police lieutenant, who was dropping off his own child.”

The shooting was the third at a U.S. middle school in the past four months after deadly incidents in Nevada in October and in Colorado last month. It is also at least the 26th school shooting in just over a year since the Newtown massacre of December 2012.