(CNN) -- A teenager has been charged with murder in stabbings at a Houston-area high school that left one student dead and three others injured, the Harris County Sheriff's Office announced Wednesday evening.
Luis Alonzo Alfaro, 17, faces one count of murder in the Wednesday morning confrontation at Spring High School, about 20 miles north of downtown Houston, the sheriff's office said.
A 17-year-old student was killed and three other students were injured. The three injured students have been released from hospitals, the sheriff's office said.
Harris County Sheriff Adrian Garcia said earlier that "there has been some information that this may have been gang-related," but he stressed that no conclusions had been reached because the investigation was in the early stages.
Information on what led to the stabbings was limited. Garcia said an encounter between students turned into a physical confrontation involving "cutting instruments of some sort."
The statement issued Wednesday evening read in part: "The stabbing occurred during a physical altercation between several students in the hallways. During the altercation, the suspect produced a knife and fatally stabbed the victim to death and injured 3 other victims."
It was unclear Wednesday night whether Alfaro had an attorney.
After the stabbings, students were kept in classrooms for safety and to allow authorities to interview witnesses, said the superintendent of Spring Independent School District, Ralph Draper. The school intended to dismiss students for the day at noon, he said.
Sheila Dauth, mother of a Spring High School freshman, said she learned of the stabbings around 7:15 a.m., when her son texted her. They continued to communicate in the hours after, while he and other students were kept in their first-hour classes, she said.
"He said he's OK. He said it was pretty scary at first when they were rushing everyone into the classrooms," Dauth said. The students have drilled for such situations, "but I don't think he expected to be in a lockdown" like this, she said.
Dauth said she was disappointed that she learned about the incident through her son and the local media hours before the school district contacted her. The district gave automated phone and e-mail messages to parents about three hours after the stabbings, she said.
Draper, while not specifying the time it took to notify parents, told reporters that the district needed to do two things before communicating with families. First was to ensure the rest of the students were safe, and second was to coordinate with authorities so that the investigation wouldn't be compromised.
CNN's Joe Sutton contributed to this report.