Police in Pennsylvania on Wednesday responded to a wave of fake active-shooter calls and bomb threats to local schools across the state just days after a former student killed six people – including three children – at a private Christian school in Nashville.

Pennsylvania State Police said it was investigating a series of phone calls made to 911 centers that involved threats against several schools in different counties.

One of several schools to receive threats, Lehighton High School, said it received a message from police of supposed gunfire at the school. Staff contacted the school district and the school was put on lockdown.

Lehighton Borough and school police conducted a search and found that the reports were unfounded. The school lockdown was lifted, authorities said.

Many of the calls received had similar content, police said.

NASHVILLE VICTIMS: GOV BILL LEE REVEALS WIFE LOST ‘ONE OF HER BEST FRIENDS’ IN COVENANT SCHOOL SHOOTING

Later Wednesday, state police said they responded to all incidents in its primary coverage areas and were in contact with municipal law enforcement partners for ongoing investigations. All schools involved have been cleared or are in the process of being cleared, state police said.

The state police barracks in Hollidaysburg said the threats were "believed to be computer-generated ‘swatting’ calls."

High School

One of several high schools that were targeted in fake active-shooter calls or bomb threats on Wednesday. (Google Maps)

"PSP Holliday and Rockview stations are responding to active shooter threats at local schools that have been called in by telephone," state police tweeted. "We are treating each incident with standard law enforcement protocols. However, the calls are believed to be computer-generated swatting calls."

Swatting in this context refers to the deliberate reporting of a false crime or emergency to prompt an aggressive response from police agencies.

CLICK HERE TO GET THE FOX NEWS APP

The scare comes two days after a 28-year-old former student broke into a Christian elementary school, the Covenant School, in Nashville, Tennessee, and killed three children and three adults. The shooting is the latest in a spate of violence in schools, including a massacre at an elementary school in Uvalde, Texas, last year; a first-grader who shot his teacher in Virginia; and a shooting last week in Denver that wounded two administrators.