A fight broke out at Spring High School in north Houston, Texas, on Wednesday morning, leaving one student dead and three injured, according to the Harris County Sheriff's Office.
Three suspects are reportedly in custody. The weapon used in the fight was described by police as a "cutting instrument."
Among the three injured students, one is currently in surgery, Sheriff Adrian Garcia told reporters.
"There has been some information that this may have been gang related, but it's a very dynamic scene and investigators are collecting information," he said.
Reports vary as to whether the fight broke out around 7 or 8 a.m.
KHOU described parents as "frustrated" over conflicting information regarding picking up their children. One father said his son texted him photos from the scene of the stabbing:
"(My son) told me that he was scared and he wants to come home. We can all understand at this point, right? ... They were walking out of the area when it happened, but they sent pictures to me of all the blood everywhere."
A reporter from Houston station KPRC was told there were "days of fights" leading up to the stabbing.