(Updates with details from sheriff, school district)
By Andrea Lorenz
HOUSTON, Sept 4 (Reuters) - One student was killed and three others injured in what police believe was a gang-related stabbing spree early on Wednesday at a suburban high school north of Houston.
Harris County Sheriff Adrian Garcia said three other students considered "persons of interest" were detained for questioning after the melee.
"There has been some information that this may have been gang related," Garcia said.
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.
Garcia said the 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 school was locked down for hours after the incident and little information was released to parents. Superintendent Ralph Draper told a news conference the school district was working with police officials at the time to ensure a smooth investigation.
Garcia said the school district's police had responded to the incident within 60 seconds, followed shortly by the sheriff's department. (Reporting by Andrea Lorenz; Writing by David Bailey; Editing by Bernadette Baum and Bob Burgdorfer)