CINCINNATI, Ohio – Administrators in numerous Ohio schools have evacuated buildings in recent weeks following a series of bomb threats called in to multiple school districts in several counties.

Yesterday, police evacuated Oakdale Elementary School in Green Township, Edgewood Schools in Butler County, and Summerside Elementary School in Union Township after bomb threats were called in around 10 a.m., the Cincinnati Enquirer reports.

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The came in at 9:50 a.m. at Summerside, 9:55 a.m. at Oakdale, and 10 a.m. at Edgewood schools by what sounded like a computer-generated or digital voice, Butler County Sheriff Richard Jones said in a news release.

“We received information that this happened in several other adjacent counties around the same time,” he said. “We do not know if they are connected or if it is the same person but it is being thoroughly investigated.

“We take any and all threats of harm very seriously,” Jones said. “This individual needs to be arrested quickly and taken off the street.”

The caller to Edgewood City School said only that the schools contains explosives, Butler County bomb squad specialist Mike Grimes told WCPO.

“He or she said there were some explosives in one of the schools but would not say which one,” Grimes said. “The caller hung up and the schools began their evacuations.”

Grimes said the call flowed an unsubstantiated report the same morning that an individual posed a threat to Talawanda High School, according to the news site.

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A Facebook post by West Clermont Local Schools claims a total of eight schools across Cincinnati received threats Wednesday morning.

All of the schools were cleared after thorough searches.

It’s the second round of threatening calls to Ohio schools in the last two weeks. On Sept. 25, threats prompted the evacuations of Meadowdale High School, Bell Creek Intermediate School, Endeavor Elementary, Liberty-Benton elementary and middle schools, North Royalton High School, Furry Elementary School and Licking Heights High School, WHIO reports.

Ohio Homeland Security is working with the Ohio Department of Education to “monitor the situation,” but it remains unclear what, exactly, is going on.

State education officials contacted all of the state’s school districts after the first incident.

“Schools should continue with their established safety plans, working with local law enforcement,” Ohio Department of Education spokeswoman Kim Norris told the news site. “Parents and students should always be alert and report anything that may seem unusual to law enforcement and the school district.”

State officials are also working with the Fusion Center, which is a regional cooperative of public safety and health agencies around Cincinnati focused on terrorism, according to the Enquirer.

The FBI is also investigating.