UPDATED: 21 Killed, Dozens Injured In Deadly Texas Primary School Shooting

 A horrific school shooting in the United States has claimed 21 lives.

The latest incident of mass gun violence in the US, saw a teenage shooter open fire at a primary school in south Texas on Tuesday, killing 18 children and three adults.

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Governor Greg Abbott said an 18-year-old man opened fire at Robb Elementary School in Uvalde, in Texas on Tuesday.

“He shot and killed, horrifically, incomprehensibly, 14 students and killed a teacher,” said the governor only hours after the shooting.

The Uvalde Consolidated Independent School District Police Chief Pete Arredondo told reporters the shooter, Salvador Ramos acted alone.

“At this point the investigation is leading to tell us that the suspect did act alone during this heinous crime,” he said.

The teenage shooter who lived locally allegedly entered the school with a handgun, and possibly a rifle, opening fire, Mr Abbott said

Gov. Abbot said the 18-year-old gunman was shot dead, likely killed by responding officers but that the events were still being investigated.

13 children were taken by ambulance or bus to Uvalde Memorial Hospital, while another hospital has reported a 66-year-old woman was in critical condition.

The deadliest school shooting in Texas' history, it comes four years after 10 people were fatally shot at Santa Fe High School in Houston.

It also marks the worst mass gun event at an elementary school since the 2012 Sandy Hook shooting in Connecticut, in which 20 children and six staff were killed.

More to come.

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