A sixth-grade girl brought a gun to her Idaho middle school, in the US, and shot and wounded two students and a custodian and then was disarmed by a teacher, authorities said. The three were shot in their extremities and were expected to survive, officials said at a news conference. Jefferson County Sheriff Steve Anderson says the girl, believed to be aged 11 or 12, pulled a handgun from her backpack and fired multiple rounds inside and outside Rigby Middle School in the small city of Rigby, about 145km southwest of Yellowstone National Park. A female teacher disarmed the girl and held her until law enforcement officers arrived and took her into custody, authorities said, without giving other details. Authorities say they're investigating the motive for the attack and where the girl got the gun.