HOUSTON — Two people were shot and two others injured when an 18-year-old student drew a gun and opened fire during a classroom fight at a Texas high school on Wednesday, police said.

Arlington assistant police chief Kevin Kolbye said a suspect, identified as Timothy George Simpkins, had been arrested after the shooting at Timberview High School in Arlington, a suburb of Dallas.

Kolbye said Simpkins, who turned himself in after fleeing the school, would be charged with three counts of aggravated assault with a deadly weapon. Police said a .45 caliber gun had been recovered.

“This is not a random act of violence,” Kolbye told reporters. “A student got into a fight and drew a weapon.”

Three people were hospitalized, two of them with gunshot wounds, the police officer said. Local media said a 15-year-old boy was in critical condition while the other injuries were not life-threatening.

A fourth person, a pregnant woman, was treated on the scene for minor injuries and released

Kolbye said more than “two or three shots” were fired.

“We know that this is a traumatic incident for these kids,” he said. “We’ve increased security with additional police officers at all of our schools in Arlington.”

The school was locked down following the shooting and Arlington police set up a secure area for parents to reunite with their children.

Television images showed a heavy police presence around the school after the shooting, with armed officers searching the sprawling campus and ambulances and fire trucks on the scene.

A fleet of yellow school buses was mobilized to evacuate students from the school after the lockdown was lifted.

Timberview High School has an enrollment of around 1,900 students.

After a year spent largely learning online, US schools have returned to the classroom, reviving the fear of on-campus shootings, with multiple small-scale incidents reported in recent weeks.

More than 256,000 students have been exposed to gun violence in US schools since 13 people were killed in the massacre at Columbine High School in Colorado in 1999, according to data compiled by The Washington Post.

The figure includes those caught up in the violence, such as witnesses, and those forced to evacuate educational institutions when gunfire erupted.

According to a Post database, there were 29 school shootings in the United States in 2018 and 27 in 2019. The Post figures do not include shootings at colleges or universities, suicides or accidental discharges.

The deadliest recent school shooting in the United States took place in 2018, when 17 people were killed by a former student at a high school in Parkland, Florida.