The suspect was arrested nearly 30 minutes after the 8 am Abilene High School incident, police spokesman Rick Tomlin said. KTXS-TV
Both victims were rushed to the Hendrick Medical Center and their conditions are unknown.
Police said the attack appeared to have been targeted and the result of a "previous fight" between at least one of the victims and the suspect, Tomlin said.
"He appeared here this morning apparently targeting the two victims directly," he said.
All three male students involved in the incident are minors and are "about 16" years old, police said.
The stabbing took place outside the school cafeteria and there was a growing police presence on campus after the attack.
The Associated Press contributed to this report.