A southwest Houston middle school was evacuated Tuesday after a bomb threat.

Officials said Johnston Middle School, 10410 Manhattan Drive, received a call about a bomb threat at 9 a.m.

As a precaution, HISD police, Houston police and Houston firefighters responded and the campus was evacuated.

Officials conducted a sweep of the school and nothing was found.

The all-clear was given a short time later and students returned to class.