Electronically transmitted threats went out Wednesday morning to more than 15 students and staff members at L.D. Bell High School and police were on the scene, a police official said.
Students were kept in classrooms for about an hour, a school official said.
The unsubstantiated threats were made against the students and staff by an unknown person, police said.
Officers were at the school at 1601 Brown Trail performing a sweep of the campus and investigating.
The threats were received about 9:30 a.m. and indicated there would be a shooting at 9:59 a.m., said Deanne Hullender, a spokeswoman for the Hurst-Euless-Bedford school district.
“We immediately notified law enforcement who are initiating a sweep of the building,” according to an email sent to Bell HIgh School parents. “As a parent, you have a unique ability to inspire calm in your student. If your student shares concerns with you, please reassure them that school staff and law enforcement are working proactively to ensure their continued safety.”
School officials planned for additional officers to remain on campus the rest of the day.
As of Wednesday afternoon, police had not located a suspect.
Detectives continued to investigate the incident.