SPRING, Tex. — A fight, possibly gang related, broke out at a suburban Houston high school early Wednesday, leaving one student dead of stab wounds and three other students injured, the authorities said.

The confrontation unfolded shortly after 7 a.m., a few minutes before classes began at Spring High School, one of the largest high schools in Harris County. The 3,500-student campus, next to Interstate 45 about 20 miles north of downtown Houston, was locked down throughout the morning. After the authorities determined that the school was secure, they kept students in classrooms to interview potential witnesses and planned to release them to their parents in the afternoon.

Adrian Garcia, the Harris County sheriff, said the confrontation might have been gang-related, and investigators were questioning three people. He said that no arrests had been made, but that all of the people investigators were interested in were in custody.

The victims and those being questioned were students at the campus, which started its school year last week. The student who was killed was a 17-year-old male junior, the authorities and parents of students at the school said. The weapon he was stabbed with has not been recovered. Two of the victims received minor injuries; the condition of the other was not immediately known.

“Every parent sends their child to school believing that school should be one of the safe-haven places, a place where they can send them and receive them back at the end of the day” said the superintendent of the Spring Independent School District, Ralph H. Draper. “It’s what I lose sleep over. In my nearly 30-year career, this is the one thing that you pray never to experience.”

The stabbing follows two other recent violent episodes at a nearby community college. In January, a dispute between two students led to gunfire at Lone Star College’s North Harris campus, a few miles south of Spring High School. Four people were sent to hospitals and the campus was evacuated. In April, more than a dozen people were stabbed at another Lone Star College campus by a troubled 20-year-old student.

The authorities said Wednesday that the sheriff’s office and the school district’s police department would provide additional security at Spring High School for the next few days. Although sheriff’s officials said they had not been called to the school about gang violence before Wednesday, the chief of the school district police force said it had created a gang task force to address the problem.

Parents rushed to the school after the attack, and expressed frustration at the slow pace of news and information from the school district.

Everett Slack, 40, was waiting to pick up his son, a 14-year-old freshman. He had dropped him off at school shortly after 7 a.m., and had returned home to get ready for work when he received a text from his son that there had been a stabbing.

“I’m a former soldier,” said Mr. Slack, an Army veteran. “The first time I saw someone dead I was 28 years old. I was a grown man. For my son to be around somebody that died at 14, I don’t know what I’m going to say to him. He shouldn’t have to deal with that. He’s a freshman in high school.”

He said that problems with violence at the school were not new. Three years ago, when his daughter was a freshman, a food fight in the cafeteria spun out of control. “The superintendent needs to do something,” he said. “Putting more police in the school, metal detectors. There has to be something that they can do to make this more efficient and safer.”