Windsor Locks High School was placed in a lockdown on Thursday afternoon after an unknown substance was found in school.
According to the town's first selectman, there is speculation that a male student brought an unknown substance to school with the intent of harming another student.
It is unclear what the substance was, but officials said it is not dangerous the way it was packaged.
Students were evacuated and taken to the football field. They were on the field until about 4 p.m.
No injuries were reported.
"We all didn't know was was going on. We thought it was an ordinary fire drill but when they told us to go to the football field, it was like the first time ever we heard that. We didn't know what was going on. Then when they told us they found an unknown substance, we were all curious and we were out there for three hours," said student Alex English.
"The circumstance was the kid brought the substance to school to threaten another child. We don't know what the substance was. They said they found out it wasn't anything harmful and apparently the other child has been taken into custody," said parent Sandy English.
Police have searched the student's home.
When students were released, parents could pick them up at a neighboring church.
Sources say the Department of Energy and Environmental Protection was called to the school to assist in the investigation.
Stay updated with Eyewitness News as more information becomes available.
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