At least 19 children and two adults have been killed in a Texas elementary school shooting.

Police said so late Tuesday after the attack in the small town of Uvalde near San Antonio;

initially there was talk of 14 fatalities.

The shooter was also dead. According to initial findings, the attacker was an 18-year-old man who had been killed by officials.

According to the police, they assume that the shooter acted alone.

There are several injured, children as well as adults.

The police did not initially release concrete figures or other details.

US President Joe Biden called for stricter gun laws.

"As a nation, we have to ask ourselves when in God's name are we going to stand up to the gun lobby," Biden said at the White House Tuesday night.

"The idea that an 18-year-old boy can walk into a gun store and buy two assault rifles is just wrong."

Biden said, visibly moved, that innocent second, third and fourth graders had lost their lives in "a massacre".

Their parents "will never see their child again, never put them to bed and be able to cuddle with them," the Democrat said.

Erick Estrada from the Texas Department of Public Safety spoke to CNN about the events leading up to the massacre.

The suspect initially shot his grandmother, Estrada said.

The incident happened in the grandmother's apartment - she was taken to a hospital.

Nothing was initially known about her condition.

Finally, the shooter drove to school in a car and caused an accident there, Estrada said.

He then got out of the car and entered the school wearing a protective vest, a backpack and a gun.

There he opened fire.

The 18-year-old was then asked by the school's security staff.

However, Estrada emphasized that the investigation was still ongoing and that this information was still preliminary.

Little was initially known about the background to the crime in Uvalde.

The investigators kept a low profile.

According to media reports, the shooter bought the weapon used in the crime about a week ago, shortly after his 18th birthday.

The shooter's behavior has recently changed, the Washington Post quoted a childhood friend of the shooter as saying.

He lived with his mother and sometimes with his grandmother and has recently been behaving aggressively.

Since the Sandy Hook elementary school massacre in Connecticut state ten years ago, there have been more than 900 incidents of reported shooting on school grounds, Biden said.

You can't prevent every tragedy with stricter gun laws - but these laws have positive effects.

Congress, the US Parliament, is responsible for tightening gun laws.

Many Republicans oppose such a move.

The gun lobby is very powerful in the US.

In his speech, Biden also remembered his son Beau, who died of cancer in 2015, and his daughter, who was killed in a car accident in 1972.

"Losing a child is like having a piece of your soul ripped out," he said.

Next to him was his wife Jill.

Biden had just returned to Washington from a trip to Asia.

Biden immediately ordered flags on all public buildings in the United States to be flown at half-mast up to and including Saturday in view of the devastating attack.