Groton ― Ella T. Grasso Technical High School was briefly placed in lockdown, and Fitch Senior High School and Groton Middle School in “secure status” on Thursday morning as state police investigated an incident at Grasso.

Police said at approximately 10:34 a.m. they responded to Grasso for a report of a “suspicious incident.” The school was temporarily put in lockdown.

Police said after investigating, they determined the incident was noncriminal, and that there was no threat to the safety of students, staff or the public.

Rebecca Kuchar Beyus, communications specialist for Groton Public Schools, said Thursday evening she did not know what had spurred the report at Grasso, but that Groton Town police had advised the middle and high schools to go into a building secure safety protocol it was being investigated. All three schools occupy the same campus, she said.

While under the protocol, no one was allowed to enter or exit the high or middle schools without administrative permission, but students could still attend lunch and class. “Ironically,” Beyus said, the schools had practiced security drills earlier that day.

The schools had lifted the protocol before noon, she said.

Grasso officials could not be reached to comment.