The “new high school” will blow up, an unidentified caller told a 911 operator Monday at 9:56 a.m.

Two cell-phone calls from an unidentified caller threatening to blow up two New Haven public schools forced the temporary closure Monday morning of the three local schools: the Cooperative Arts and Humanities Interdistrict Magnet school on College Street, New Horizons School for Higher Achievement on Hallock Avenue and the New Haven Academy on Braddock Street, said Michelle Wade, New Haven Public Schools’ director of communications. Though the New Haven police descended on the schools and students were moved to secure locations, no bombs were found. Though Wade said such threats happen on occasion, she added that Monday’s shake-up nonetheless demonstrates that the school district is prepared to deal with them.

“We take these types of situations very seriously,” Wade said. “We worked closely and collaboratively with the police department, and every school has a security plan and protocol to act accordingly.”

While Wade said she does not know exactly how many bomb threats New Haven public schools have received during her nearly 14-month tenure as director of communications, she said Monday’s calls were not the first. City Hall spokesperson Jessica Mayorga said the city took appropriate steps Monday to ensure the safety of the students and staff at each school involved.

The prank caller has not yet been identified, NHPD spokesman Joe Avery said, but the department is currently tracking the cell phone from which the call was made. Avery said he is confident the police will be able to find out the culprit’s identity.

Still, the calls disrupted much of the school day for students at two public schools.

After the NHPD received the first call, armed with bomb-defusing technicians and canine units, they descended on the Co-op School, which opened its doors just over a year ago, said NHPD spokesman Joe Avery. Since Co-op used to be located where New Haven Academy currently is, police also searched the academy in case the caller’s message was referring to the Co-op School’s former location. Unlike Co-op and the New Horizon School, the academy was not evacuated as police went through the building. But the police maintained a presence at the academy throughout the day.

In the meantime, students were evacuated from Co-op at 10:55a.m., Wade said. While the school was being searched, the students were moved into the Shubert Theater on College Street. No explosive devices were found, though, and when the police ruled the building safe students were allowed back into the building at 11:27a.m. to continue with their classes.

At almost the same time as the first 911 call came in, another 911 call threatened to use explosive devices at the New Horizons School, Wade said. The building was promptly checked for explosive devices, and since none was found there either, students were permitted to reenter the school shortly after 11:30 a.m.

Ward 7 Alderwoman Frances “Bitsie” Clark said Monday’s events do not reflect poorly on New Haven school systems’ security or that of her ward.

“Naturally, any time you have a bomb threat, there’s a concern,” Clark said “But these sorts of false alarms happen all the time to schools, courthouses and other buildings.”