A gunman has shot and killed 14 students and one teacher at an elementary school in South Texas, Governor Gregg Abbott said.
Mr Abbott said the suspect, who the governor identified as 18-year-old Salvador Ramos, was himself killed, apparently by police officers responding to the scene.
Official details on the circumstances of the midday shooting remained sketchy in the immediate aftermath of the violence, which unfolded at Robb Elementary School in the town of Uvalde, Texas, about 80 miles west of San Antonio.
Mr Abbott told a news briefing: "He shot and killed horrifically, incomprehensibly, 14 students and killed a teacher.
Armed police at the scene of the shooting
MARCO BELLO
A school employee talks through the window of a school bus to one of the parents near the scene
MARCO BELLO
"Mr. Ramos, the shooter, he himself is deceased and its believed that responding officers killed him."
A tweet from the Uvalde Consolidated Independent School District said earlier: "There is an active shooter at Robb Elementary.
"Law enforcement is on site. Your cooperation is needed at this time by not visiting the campus. As soon as more information is gathered it will be shared. The rest of the district is under a Secure Status."
It later wrote: "Parents are asked to pick up students at the regular dismissal times at the child's campus.
"There will be no bus transportation. Officers will be on site to escort students to the parents cars. Parents please be patient as lines will be long."