COBB COUNTY, Ga. — WSB has learned that at least two metro high schools were placed on lockdown Tuesday after bomb threats were called in.

According to Johns Creek police, Northview High School was placed on lockdown. In a letter to parents, it said at least three metro schools had threats called in on Tuesday.

“Johns Creek Police immediately responded to our campus, checked our parking lot and quickly determined that there was no threat. We also had our School Resource Officers sweep the interior of our building to ensure the safety of all our students,” the letter said. “While learning was not disrupted in any way, a disturbing incident like this can cause unease amongst our students and staff.”

In Cobb County, Walton High School was also placed on lockdown.

“Our team immediately reported the threat to multiple law enforcement agencies, which are now actively investigating the situation. Currently, while there is an increased law enforcement presence, there has been no interruption to the school day, and dismissal is on schedule,” the school district said in an email to parents.

WSB learned the threat has been cleared at Walton High School.

“Over the last few weeks, in the wake of the tragedy in Barrow, over 60 reported threats have been called into schools around the county. Almost all of these incidents were the result of bad behavior on the part of people who are seeking to disrupt the school day,” the letter continued.