HOUSTON (Reuters) - One student was killed and three others injured in what police said may have been a gang-related stabbing early on Wednesday at a suburban high school north of Houston.
Three other students considered "persons of interest" were detained for questioning after the melee, Harris County Sheriff Adrian Garcia said.
"There has been some information that this may have been gang related," Garcia said.
Garcia said the unidentified student who died at Spring High School was 17 years old and two other students sustained minor injuries.
The third injured student was transported by helicopter to Memorial Hermann Texas Trauma Institute and was listed in good condition, hospital spokeswoman Alex Rodriguez said.
"We believe that a confrontation of some sort occurred ... that ultimately led to a physical confrontation that then produced weapons," Garcia said, adding that authorities were still looking for the "cutting instruments of some sort."
The high school was locked down for hours after the incident and little information was released to parents.
Frustrated parents, standing in the sweltering heat across the street from the school, initially learned of the incident through local media reports or through text messages from their children who were inside the school.
"One of my girlfriends called to ask if I'd heard," said Cheri Fitzgerald, the mother of a freshman, who did not get an automated message from the school until 10 a.m. local time, about three hours after the incident occurred.
Another parent, Tricia Mollard - who heard about the fight on television, tried calling the school and then police for answers.
"No one could tell me anything. Then I called the school district asking questions and she hung up on me. The lady I spoke to hung up. I am so mad. I want answers," she said.
Superintendent Ralph Draper told a news conference the reason for the delay in communicating with parents was that the school district was working with police officials at the time to ensure a smooth investigation.
School principal Donna Ullrich later said in a statement on the school's website she is keeping parents informed with regular updates by phone and email messages throughout the day.
Parents said some students go to school before classes begin in the morning to get breakfast, causing the cafeteria to be crowded without much adult supervision.
Other parents said many of the entrances to the school, which does not have metal detectors, are unsupervised.
"Someone told me that kids are safer walking the streets of Houston than they are at Spring High School. I wish I'd known that," said Stacy Thornton, whose family is new to the district.
The stabbing was the third such violent incident at a Houston area school this year. Fourteen people were stabbed, but none killed, at a community college campus in April, and three people were wounded in a shooting at another community college campus in January.
Additional Reporting by Andrea Lorenz; Writing by Brendan O'Brien; Editing by Greg McCune, Bernard Orr