Two children injured after 12-year-old student opened fire at a middle school in Roswell, New Mexico, south west of United States.Officials said the suspect is in custody and a 11-year-old boy and a 13-year-old girl were being treated at a hospital. The shooting occurred about 08:00 local time (15:00 GMT) Tuesday at Berrendo Middle School as classes started. A teacher convinced the student, who allegedly carried the firearm in an instrument case, into dropping the weapon, Governor Susana Martinez said.He was “quickly stopped by one staff member who walked right up to him and asked him to set down the firearm, which he did,” Martinez said.University Medical Center in Lubbock, Texas, spokesman Eric Finley said the injured boy, initially reported as a 14-year-old, was flown there in critical condition, while the 13-year-old girl was in serious condition.Police officials said investigators were still looking into a possible motive, but New Mexico State Police Chief Pete Kassetas said he wanted to assure residents police had the only individual responsible for the shooting in custody.