Threat deemed unfounded after Grapevine-Colleyville ISD secures multiple campuses, officials say

An anonymous threat at Colleyville Heritage High School prompted multiple Grapevine‑Colleyville ISD campuses to enter a secure protocol Friday afternoon, officials said.

Shuttles were halted and dismissal times adjusted while police assessed the situation, according to the district.

Grapevine and Colleyville police investigated and later determined the threat was unsubstantiated.

"There was no credible threat to our schools or campuses, and the incident has been resolved," the district said in a statement.

In addition to Colleyville Heritage High School, the district placed Heritage Elementary, Heritage Middle, Early Childhood Development Center, and the offices of iUniversity Prep under secure protocols.

Normal operations continued inside the schools, but exterior doors were locked, and no visitors were allowed, the district said.

According to officials, the dismissal proceeded normally – with extra police presence – at Heritage Elementary, Heritage Middle, and the Early Childhood Development Center.

The secure protocol at Colleyville Heritage High was lifted shortly after 4 p.m., and dismissal occurred as usual.

"The safety and well-being of our students and staff remain our highest priority," the district said. "We appreciate the cooperation of our students, staff, and families as law enforcement and district safety personnel responded to this situation."

CBS News Texas will provide updates as more information becomes available.