All Clear at St. John's Prep After 'Swatting,' Officer's Gun Fires ...

An active shooter was reported at St. John's Prep school in Danvers, Massachusetts, on Monday, but the school later said it's believed to have originated with a "swatting" incident and said everyone there was safe.

A Danvers police officer's gun accidentally went off as law enforcement cleared the locked-down school, prompting an elevated response, since gunfire was heard, officials said.

"The initial response was a threat of a person threatening to cause harm in one of the men's rooms. Officers responded. During the initial search, there was an accidental discharge. No one was injured and that prompted the increased response," Danvers Police Chief James P. Lovell said at a news conference.

Both the source of the initial call and the officer's accidental gunfire, which prompted a new round of 911 calls, remained under investigation Monday afternoon.

Students, faculty and staff were sheltering in place as the incident unfolded, an alert on the school's website had said. Some students fled on their own — state police said some were found in the woods.

As buildings were cleared, officials at the school brought students to a tent that had just been used for commencement. The head of school at St. John's Prep, Ed Hardiman, said his message for students was that they'd need to come together to ensure everyone could process what happened.

"Some of us are going to be okay, some of us are going to be really traumatized," Hardiman told reporters.

Read St. John's full statement announcing the all-clear was given:

Earlier this afternoon there was a report of an active shooter on campus at Benjamin Hall. Danvers and State police reported to campus and the school entered an enhanced lockdown protocol. We believe that St. John's was the victim of a Swatting call. Everyone is safe, there have been no injuries and police are currently clearing campus buildings as we account for all students.

We ask that parents do not come to campus at this time. Please go to the Stop and Shop parking lot on route 62 in Danvers and await further instruction. As we are cleared to release students we will communicate that process to parents via phone and/or email.

The initial statement released from the school said: "There has been a report of an active shooter on campus at Benjamin Hall. Danvers and State police are on site. Students, Faculty, and Staff are sheltering in place.We will further provide updates as soon as possible."

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"Swatting" incidents are hoax calls intended to bring out police when there is no danger. Waves of school swattings have been reported across Massachusetts and the country in recent months.

Over a few days in February, schools across Massachusetts were hit with hoax calls, canceling classes for thousands of students and prompting an FBI investigation.

State police said the size of the 175-acre school necessitated such a large response.

Students returned to class on Wednesday unsure if they will be disrupted again after thousands of students across more than a dozen Massachusetts schools were impacted by “swatting” calls

A massive police presence was seen at St. John's Monday afternoon after the threat was reported at Benjamin Hall.

State police said that no threat was identified and no one was found injured, but dozens of officers continued to investigate. Parents of St. John's students were asked to head to reunite with their children at a Stop & Shop on Route 1 in Danvers.

St. John's is a 116-year-old all-boys Catholic middle and high school with about 1,450 students.

An active shooter threat was reported at another Massachusetts Catholic school on Monday — at Boston College High School. Boston police said that incident appeared to be a case of "swatting," a hoax call intended to bring out police when there is no danger.

It wasn't immediately clear if the two incidents were related.

Elsewhere in the North Shore, the report of a threat at St. John's prompted a lockdown measure at another school, Essex North Shore Agricultural & Technical School. It eventually canceled after-school activities.