Authorities believe the shooting was student-on-student violence.
DALLAS -- Several hours after four students were injured in a shooting at Wilmer-Hutchins High School in Dallas on Tuesday, police said the suspect in the gunfire was taken into custody.
The arrest was announced in a news release from the Dallas Independent School District on Tuesday evening. No other details were provided.
Preliminary information indicated that the shooting was student-on-student violence and not an active shooter situation, multiple sources told ABC News.
The four injured students were transferred to area hospitals, according to Dallas ISD Police Department Assistant Chief of Police Christina Smith, who did not provide more details on their conditions.
During a news conference earlier Tuesday, officials said they had identified the suspected shooter but had not yet made an arrest.
At least one student was shot in the leg, sources said.
At the news conference, Smith said she did not have information on what led to the shooting, calling it a "very fresh investigation."
The gun used in the shooting "did not come through during regular intake time," she said.
"It was not a failure of our staff, of our protocols, of the machinery that we have," Smith said, though she did not elaborate.
A senior student told Dallas ABC affiliate WFAA that he was in the foyer when, around lunch time, he heard a few gunshots. He said he then saw students running and heard screaming, and he took cover in the band room.
Video shows students evacuating the school as police cars and fire trucks gathered at the scene.
The school has been secured, the Dallas Independent School District said, but people are urged to stay away from the campus.
All high school students were reunified with their parents and guardians, according to Superintendent Stephanie Elizalde.
There will be no school the rest of the week, and mental health professionals will be made available, she said.
"Today, as we all know, the unthinkable has happened," Elizalde said during the briefing. "And quite frankly, this is just becoming way too familiar, and it should not be familiar."
Texas Gov. Greg Abbott said that he has offered the school district support and provided law enforcement with "the tools they need to arrest the criminals involved and bring them to justice."
"Our hearts go out to the victims of this senseless act of violence at Wilmer-Hutchins High School," he said in a statement on X.
ABC News' Luke Barr, Josh Margolin, Aaron Katersky and Alex Stone contributed to this report.