HOUSTON – Westside High School parents received a letter Friday morning after a threat was made against the school on a Facebook page used by a group called "Aint Clownin Around."

The threat was posted Thursday on a page that has since been deactivated. It threatened that the group would be at schools Friday to either kidnap students, or kill teachers going to their cars.

"Extremely concerned because this seems to be a recurrence. I mean, it's basically almost daily and he's my life," parent Diana Crossley said.

Another social media page listed seven schools in southeast Texas, apparently in connection with the other threat, calling those locations "main targets."

"It's definitely something that is scary. I have a newborn now so it's something I think about a lot. But pretty much, just pray and hope that might kid is safe while she's at school," parent Eric Reed said.

One of the schools on the list was Westside High School, where officials sent a letter to parents about the threat.

"This is Principal Stewart at Westside High School to inform you of an anonymous threat social media made against schools, including ours, which has been circulating in the region and in other states," the letter said. "We immediately notified (Houston Independent School District) Police, and officers determined the threat was not credible. However, HISD Police have assigned extra officers to patrol our campus as a precautionary measure."

The letter went on to say that visitor access will be restricted Friday to only essential school staff, and that extra HISD police officers are patrolling the campus today.

A similar letter was also sent to parents of students at Northside High School, Tanglewood Middle School and the Spring Independent School District.

"I got scared. I'm from Norway so I'm not used to this. I was thinking of picking him up but I'm here now," parent Nina Kjelsas said.

In a letter sent to parents of Bay City Independent School District, officials said that a precautionary lockdown was enacted at Bay City High School and Cherry Elementary School because of the rumors.

Houston police said they are also investigating the threat, but do not deem it credible at this time.