The Houston Independent School District was operating as usual Thursday morning after receiving a threat of violence the night before similar to those received this week by school districts across the nation including Los Angeles, New York and Miami.

HISD Police Chief Robert Mock reiterated at a press conference Thursday that the threat was not believed to be credible after it was apparent that it was being sent to multiple locations and not specific to HISD. “That’s a big red flag,” Mock said.

The email was sent around 8 p.m. Wednesday to HISD Superintendent Terry Grier among others in the district. HISD police began investigating and contacting other law enforcement agencies and school districts. The investigation into the origin of the email is continuing.

As a precautionary measure, law enforcement officers are patrolling throughout the district Thursday to ensure student safety. No issues have been reported, and Mock said classes were running normally.

HISD will continue to update parents, students and staff should new information become available.  Text messages can also be received by texting “Yes” to 68453.

Below is the text of phone call made to parents and staff this morning:

This is the Houston Independent School District calling with an important update for parents and students. As you know, last night HISD was one of many school districts across the country to receive a threat of violence that police do not believe is credible. Please know that school is in session today, and no issues have been reported. Teaching and learning are continuing as usual. Though the threat is not believed to be credible, we are taking every precaution possible to ensure safety. Law enforcement officers conducted random sweeps of school district buildings last night. Area law enforcement agencies have been notified and additional officers from HISD police and law enforcement agencies throughout the greater Houston area are patrolling our district today. Please know we take situations such as this very seriously and investigate all threats, as the safety of our students and staff is our top priority. We appreciate your continued patience and support and will provide you with additional information as it becomes available. Again, this was the Houston Independent School District calling with an important message for parents and students.