Three New Jersey schools were put into lockdown Friday after school officials believed there to be threats against students and teachers.

Two of the lockdowns were in Morris County at the Morris County Vocational Technical School in Denville and at Parsippany Hills High School. The schools are less than a mile apart, but officials say that the lockdowns were not related.

Authorities say that comments made by a Parsippany Hills High School student triggered the lockdown there. The school was on lockdown for about 20 minutes while authorities investigated. The threat was determined to be unfounded.

But the feeling of fear was so intense for some students that one of them was seen on cellphone video breaking a window and jumping out to escape. Officials say that student was treated for minor injuries.

Officials say that a social media post triggered the lockdown at the Morris County Vocational Technical School. School officials were alerted to the post around 7:35 a.m. Friday.

“About like two minutes after I walked in the school, I heard on the announcements that the principal was telling us to go inside a classroom because it was a lockdown and it wasn’t a drill,” one student told News 12 New Jersey.

Officials say that this social media post was actually intended for the Passaic County vocational school, which was also put into lockdown. Law enforcement officers say that this threat was also determined not to be credible.

The Morris County vocational school’s superintendent says that they are prepared for these types of incidents.

“Unfortunately nowadays in education, we have to do a lot of thinking and planning for days like today,” says Superintendent Scott Moffitt.

The lockdowns come just days after several school shooting incidents across the country.