HISD says the calls were sent out to Northside High School, Westside High School, Lamar High School, as well as Tanglewood Middle School.
Students at Westside High School eagerly read some of the Instagram and Twitter posts to Eyewitness News.
"We'll be at all high schools this Friday either to kidnap students or teachers going to their cars," read student Sydney Freeman, who added she's not that concerned. "I think it's just like an early Halloween joke. I know October starts tomorrow. I think people are just playing around."
"It's kind of really dumb, honestly, I don't understand why people are doing this, I feel like people are doing this as a joke," said student Emily Arnautuvic.
The clown based threats have been spreading across the country in recent weeks, leading to school closures, worried parents and arrests. In the Houston-area, other school district, like Alief ISD, also sent out letters to parents.
Moms who are not on social media on a regular basis were caught off guard by the threats.
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"I don't have any clue yet here, like what's going on here, that really scares me," said Paula Saoma, whose son is in his first-year of classes at Tanglewood Middle School.
So far, there have not been any arrests in the Houston-area, though police are investigating. All school districts told Eyewitness News that they are taking these clown threats seriously. However, none of the threats so far in the area are seen as credible.