Nineteen children were among at least 21 people killed Tuesday when a man opened fire at a primary school in Texas, United States, officials said.

The suspected gunman, identified by Governor Greg Abbott as 18-year-old Salvador Ramos, was also killed.

Texas Department of Public Safety spokesman Erick Estrada told CNN that 19 children and two adults were killed in the shooting at Robb Elementary School in the town of Uvalde, about 83 miles (133 kilometers) from San Antonio and about 70 miles from the Mexico border.

"It is believed that he abandoned his vehicle, then entered into the Robb Elementary School in Uvalde with a handgun, and he may have also had a rifle," Abbott said at a press conference.