The archbishop of San Antonio comforts families following a deadly school shooting at Robb Elementary School in Uvalde.

Video. Scene at Texas school where gunman killed children

An 18-year-old gunman opened fire Tuesday at a Texas elementary school, killing many children, one teacher and injuring others, Gov. Greg Abbott said.

An 18-year-old gunman opened fire Tuesday at a Texas elementary school, killing many children, one teacher and injuring others, Gov. Greg Abbott said.

It was the deadliest shooting at a U.S. grade school since the shocking attack at Sandy Hook Elementary in Newtown, Connecticut, almost a decade ago.

The gunman entered Robb Elementary School in Uvalde with a handgun and possibly a rifle, Abbott said. Officials have not revealed a motive for the shooting, but Abbott identified him as Salvador Ramos and said he was a resident of the community that's about 135 kilometres west of San Antonio.

Abbott said the shooter was likely killed by responding officers but that the events were still being investigated. Uvalde Consolidated Independent School District Chief of Police Pete Arredondo said at a news conference that the gunman acted alone.

It was the deadliest school shooting in Texas history.