Tomball High School was evacuated as a safety precaution around 11 a.m. April 30 after a bomb threat at the campus, according to the Tomball Police Department.

After students and staff were evacuated safely, police conducted a physical search of the school and also did a K9 bomb sweep of the area. The search turned up nothing, and police cleared students and staff to return to class, according to TPD officials.

"Law enforcement responded quickly and did a great job," said Staci Stanfield, director of communications for Tomball ISD. "Students and staff returned after local law enforcement cleared everything. We were very comfortable that the campus was secure and the school was safe."

Stanfield said TISD notified parents via text message about the bomb threat and evacuation and again once the campus was secure and students and staff returned to class.

TPD detectives are conducting a criminal investigation, and those with information are asked to call the department at 281-351-5451.