Houston, May 25: In one of the worst school shootings in American history, an 18-year-old gunman has killed 21 people, including 18 children, and rendered several other grievously injured at an elementary school in Texas state, before the assailant was eliminated in police firing. Gunshots rang out of Robb Elementary School in Uvalde town, Texas, 134 km from San Antonio, at about 11.30 AM on Tuesday.

Texas Governor Greg Abbott identified the killer as Salvador Ramos, a resident of the area where the school was located. The shooter's motive remains unclear. "He shot and killed horrifically, incomprehensibly. Fourteen students and a teacher killed," Abbott said in the evening; later the toll was raised to 18 children and three adults dead. Two law enforcement officers were shot but are expected to recover, Abbott said.

Ramos was armed with a handgun and an AR-15 semiautomatic rifle, law enforcement sources confirmed. The shooter also carried high-capacity ammunition magazines. US President Joe Biden Says 'We Have to Act' After Texas School Shooting.

Names of the deceased and other details were yet to be released. According to the school website, its students are aged between 5 years and 11 years.

Chief of Police, Uvalde, Pete Arredondo said the "mass casualty event occurred at Robb Elementary School at about 11:32 this morning". He said the killer acted as an lone wolf - who was shot dead in police exchange.

The deceased children are in the second, third and fourth grades - aged between 7 years and 10 years, he said. US President Joe Biden was briefed on the shooting during his return flight from Japan where he attended the Quad Summit.

Biden will address the media on the shooting in the evening after he returns to Washington, his Press Secretary Karine Jean-Pierre said. In a tweet, Jean-Pierre wrote: "His (Biden's) prayers are with the families impacted by this awful event". Biden has ordered the US flag to be flown at half-mast until sunset on Saturday May 28, in memory of those killed in Texas.

The US flag across all public buildings, grounds, military posts, naval stations, naval vessels, embassies, consular offices and military facilities will be in half-mast. In Uvalde, all schools were locked once the gunshots were heard.

In addition to the confirmed deaths, a number of people have been injured. No number on the injured has been released. Texans across the state grieved for the victims.

Abbott said: "Cecilia (wife) and I mourn this horrific loss and we urge all Texans to come together to show our unwavering support to all who are suffering."

Abbott said he had instructed the Texas Department of Public Safety and the Texas Rangers to work with the local law enforcement to investigate the shooting.

A disturbing message on the school's website read: "Robb Elementary Parents, please do not pick up students at this time. Students need to be accounted for before they are released to your care. You will be notified to pick up students once all are accounted for."

Officials said the city's civic center was being used as a reunification center where the kin of victims can procure information from the state and coordinate other functions. The South Texas Blood and Tissue Center issued a public appeal for blood donations. They have already sent over 15 units of blood and are running out.

There is currently a blood shortage at the local hospitals where the wounded are being treated. Emergency blood donation appointments are being held for Wednesday. The shooting stoked the fiery debate on guns control.

Texas Attorney General Ken Paxton said teachers should be armed to stop such incidents in the future. Speaking to a conservative news outlet, Newsmax, Paxton said "Having potentially teachers and other administrators be armed would help stop future attacks while authorities arrived."

"First responders typically can't get there in time to prevent a shooting. It's just not possible unless you have a police officer on every campus," he said. "I think you're going to have to do more at the school."

US Senator John Cornyn (R-TX) said in a tweet: "Today, the entire state of Texas is in mourning. The shooting at Robb Elementary School is every parent and teacher's worst nightmare. My heart goes out to those in the hospital receiving care and to the loved ones of those who lost their lives. As a parent, I cannot imagine the pain they must be feeling."

"I am in touch with local officials in Uvalde and plan to travel there as soon as I can get there. No parent, child, or teacher should ever have to wonder whether it's safe to go to school. This is an excruciatingly painful time for the tight-knit Uvalde community and for all Texans”.

Texas Senator Ted Cruz described the Uvalde shooting as "truly horrific", but said gun reforms were not the way to prevent such crimes. Speaking to reporters, he said that restricting the rights of "law-abiding citizens... doesn't work. It's not effective. It doesn't prevent crime."

He said "going after felons" is what prevents such crimes and he criticised other politicians for trying to "advance their own political agenda" by calling for gun control. US President Joe Biden Blames Texas School Shooting on 'gun Lobby,' Demands 'gun Laws'.

He added that from past experience, armed law enforcement on campus is the most effective way of keeping children safe. "We don't know the details of what happened at Robb Elementary School, but there will be a lot of time to examine what steps could have been taken proactively to enhance the safety and security of the school right now," he said.

(This is an unedited and auto-generated story from Syndicated News feed, LatestLY Staff may not have modified or edited the content body)