SAN ANTONIO, Texas (ANI/Big News Network): The death toll in the mass shooting incident at a school in Texas now stands at 21 including nineteen children and 2 adults.

UN Secretary-General Antonio Guterres has extended his heartfelt condolences over the mass shooting.

Taking to Twitter, the President of the United Nations General Assembly, Abdulla Sahid said, "Deeply saddened to know about the horrific indiscriminate firing at an elementary school in Uvalde, Texas that killed twenty-one people, including 19 children. Heartfelt condolences to the parents, siblings, family members, friends community members bearing this unimaginable anguish."

The shooting took place on Tuesday (local time) after an 18-year-old gunman opened fire at Robb Elementary School in Uvalde, about 80 miles (130km) west of San Antonio, Texas. The gunman, identified as Salvador Ramos, who had been a student at Uvalde High School, was later killed by law enforcement officers.

Ramos had shot his grandmother prior to embarking on his shooting spree at the school, which has 600 pupils, all aged between seven and 10. Ramos's grandmother remains hospitalized in critical condition.

The gunman allegedly on Saturday posted on Instagram photos of two AR15-style rifles he had bought.

"When will these insane acts of violence end; it is too great a burden to bear. The word tragedy doesn't begin to describe what occurred. These massacres cannot be considered 'the new normal,'" the Archbishop of San Antonio, Texas, Gustavo Garcia-Siller, said in a statement. "The Catholic Church consistently calls for the protection of all life; and these mass shootings are a most pressing life issue on which all in society must act, elected leaders and citizens alike."

The Uvalde Consolidated Independent School District (UCISD) in Texas said they are cancelling all school activities after the shooting at Robb Elementary School for the rest of the year.

This is the deadliest attack since the 2018 Marjory Stoneman Douglas High School shooting in Parkland, Florida, where 17 people were killed, according to CNN.

Meanwhile, U.S. President Joe Biden asked Americans to stand up to the gun lobby and urged members of Congress to implement immediate gun control legislation, as he highlighted that 'sensible gun laws' need to be passed in the wake of the Texas school shooting.

"When we passed the Assault Weapons Ban (in 1994), mass shootings went down. When the law expired [in 2004], mass shootings tripled. The idea that an 18-year-old kid can walk into a gun store and buy assault weapons, it's just wrong," Biden said.

As a mark of respect for the victims, the President ordered that flags will fly at half-mast at the White House, government offices, military and naval bases, and embassies throughout the world until Saturday.

Following his return from Asia, Biden will address the nation on the school shooting incident this evening at 8:15 p.m. ET from the White House. (ANI)