UVALDE, TEXAS (REUTERS) - A teenage gunman murdered at least 19 children and two teachers after storming into a Texas elementary school on Tuesday (May 25), the latest bout of gun-fuelled mass killings in the United States and the nation’s worst school shooting in nearly a decade.

The carnage began with the 18-year-old suspect, identified as Salvador Ramos, shooting his own grandmother, who survived, the authorities said.

He fled that scene and crashed his car near Robb Elementary School in Uvalde, Texas, a town about 130km west of San Antonio. There he launched a bloody rampage that ended when he was killed, apparently shot by police.

The motive was not immediately clear.

Law enforcement officers saw the gunman, clad in body armour, emerge from his crashed vehicle carrying a rifle and “engaged” the suspect, who nevertheless managed to charge into the school and open fire, Texas Department of Public Safety Sergeant Erick Estrada said on CNN.  

Speaking from the White House hours later, a visibly shaken President Joe Biden urged Americans to stand up to the politically powerful US gun lobby, which he blamed for blocking enactment of tougher “common-sense” firearms safety laws.  

He ordered flags flown at half-staff daily until sunset on Saturday in observance of the tragedy.  

The authorities said the suspect acted alone.

Governor Greg Abbott said the shooter was apparently killed by police officers, and that two officers were struck by gunfire, though he said their injuries were not serious.

After confusing early accounts of the death toll, Texas public safety officials said on Tuesday night that 19 school children and two teachers had died.

The community, deep in the state’s Hill Country region, has about 16,000 residents, nearly 80 per cent of them Hispanic or Latino, according to US Census data.

The school’s student body consists of children in the second, third and fourth grades, according to Mr Pete Arredondo, chief of the Uvalde Consolidated Independent School District Police Department, who also addressed reporters.

Pupils in those grades would likely have ranged in age from seven to 10.

“My heart is broken today,” school district superintendent Hal Harrell told reporters late in the day, his voice quaking with emotion. “We’re a small community and we need your prayers to get us through this.”

A group of about 40 family members was led out of the Willie de Leon Civic Centre at around 11.30pm. Some broke down in the parking lot, wailing and clinging to one another as police escorted people to their cars.  

Mr P.J. Talavera, who runs a martial arts school in town, was outside the civic centre and said his wife’s niece was among the children killed.  

Mr Talavera said the town was in a state of “controlled chaos” in the moments just after the shooting, as false rumours spread of other shooters attacking different schools.  

“It’s surreal. It’s unbelievable. There is a hollow emptiness inside,” Mr Talavera said.

The carnage unfolded just 10 days after 10 people were killed in Buffalo, New York,  in a predominantly black neighbourhood. 

The authorities have charged an 18-year-old man who they said had travelled hundreds of miles to Buffalo and opened fire with an assault-style rifle at a grocery store.

Tuesday’s bloodshed in Texas began when the suspect shot his grandmother before going to the school, Texas Department of Public Safety officer Chris Olivarez said on Fox News, a development Mr Abbott mentioned earlier in the day.

“I have no further information about the connection between those two shootings,” the governor said.

University Hospital in San Antonio said on Twitter that it had received two patients from the shooting in Uvalde, a 66-year-old woman and a 10-year-old girl, both listed in critical condition.

Uvalde Memorial Hospital said 15 students from Robb Elementary were treated in its emergency room, with two transferred to San Antonio for further care, while a third patient transfer was pending. It was not immediately clear whether all of those students survived.

A 45-year-old victim grazed by a bullet was also hospitalised at Uvalde Memorial, the hospital said.

Hours after the shooting, police had cordoned off the school with yellow tape. Police cruisers and emergency vehicles were scattered around the perimeter of the school grounds.

Uniformed personnel stood in small clusters, some in camouflage carrying semi-automatic weapons.

The Texas rampage was the latest in a series of mass shootings in US schools that have shocked the world and fuelled a fierce debate between advocates of tighter gun controls and those who oppose any legislation that could compromise the right of Americans to bear arms.

The shooting in Texas was one of the deadliest at a US school since a gunman killed 26 people, including 20 children from five- to 10-years old, in a rampage at Sandy Hook Elementary School in Connecticut in December 2012.

In 2018, a former student at Marjory Stoneman Douglas High School in Parkland, Florida, killed 17 students and educators.

Firearms became the leading cause of death for US children and adolescents in 2020, surpassing motor vehicle accidents, according to a University of Michigan research letter published in the New England Journal Of Medicine last month.

End-of-year plans shattered

The children at Robb Elementary School were two days away from their summer break when Tuesday’s massacre unfolded.

They had visited the zoo and participated in a gifted-and-talented showcase, recent posts on the school’s Facebook page showed.

Tuesday was awards day, according to the calendar, and students were invited to wear a nice outfit and fun shoes as part of a “footloose and fancy” theme.

But a note was posted at 11.43am: “Please know at this time Robb Elementary is under a Lockdown Status due to gunshots in the area. The students and staff are safe in the building,” it read. 

A second post was more explicit: “There is an active shooter at Robb Elementary. Law enforcement is on site.”

Administrators asked parents to stay away. The school serves about 570 children in second through fourth grades, nearly 90 per cent of them Hispanic.

The details that came next were devastating: an 18-year-old gunman had opened fire at the school, killing 18 children and one adult, officials said.

Messages poured in from around the world, offering prayers and expressing outrage at yet another US mass shooting.

“Our hearts are breaking for the families that have been affected by this evil,” Susan Vanderwier of Indiana wrote on the school’s Facebook page.

The school district said the elementary school, where the mission statement is "Live. Learn. Love. Lead" would remain closed for the final days of the school year.

The US is the most heavily armed society in the world, according to Geneva-based research group Small Arms Survey.

Small rural states where gun ownership is widespread have disproportionate influence in the US Senate, where a supermajority of 60 votes is needed to advance most legislation in the 100-seat chamber.