GROTON, Conn. (WTNH) — Groton Middle School went into lockdown Thursday morning after a staff member found a gun lock on a school staircase, police said.

The Groton Police Department said that they responded to the middle school at 10:16 a.m. and began a safety investigation throughout the school.

The Connecticut State Police’s Violent Crime Task Force, who were in the area, also responded.

According to police, officers didn’t find any additional items or threats associated with the school. School officials lifted the lockdown at 12:50 p.m. and school activities resumed as normal, police said.

Groton police ask anyone with information about this or any other matter to call 860-441-6712.