On the cusp of a long holiday weekend, at least nine Massachusetts schools received chilling, automated phone messages Friday warning that bombs would detonate in the buildings “in the very near future,” officials said.
Authorities said no explosive devices were found at any of the schools targeted in Boston, Arlington, Bourne, Mashpee, Falmouth, Weymouth, and Barre between approximately 11:30 a.m. and 1:40 p.m.
But the schools were either evacuated or placed into safe mode, and the threats sparked an investigation that included state and federal authorities in Massachusetts and Maryland, where similar calls have been reported in recent days.
A separate threat unrelated to the robo calls was also received Thursday night in Chelsea, officials said.
David Procopio, a Massachusetts State Police spokesman, said in an e-mail that the automated threats in the Commonwealth were “robo calls in which a recorded voice indicated [that a] device would explode in the very near future.”
He said he did not know whether the affected schools would close Tuesday, but “with all of them cleared, we would expect they will be open.”
Procopio said investigators “don’t take these threats lightly. Per state law, bomb threats to schools are not merely charged as a general threat to commit a crime or as annoying and harassing phone calls. Rather, the relevant statute has very severe potential penalties if an individual is found guilty of such a crime.”
The office of Massachusetts Fire Marshal Stephen D. Coan said in a statement that the probe involved “several law enforcement agencies, including federal agencies as similar threats were experienced in Maryland today as well.”
An FBI spokeswoman said the agency was assisting but declined further comment.
The schools threatened Friday in Massachusetts were Boston College High School in Dorchester, Arlington Catholic High School and the Saint Agnes School in Arlington, the Abigail Adams and Maria Weston Chapman middle schools in Weymouth, Bourne High School, Quabbin Regional High School in Barre, Falmouth High School, and Mashpee Middle-High School.
An Arlington police spokesman said Friday that there were no plans to cancel school next week.
Falmouth Superintendent Nancy Taylor also said there will be no cancellations, nor will there be any heightened police presence beyond the resource officer normally assigned to the high school.
Patricia M. DeBoer, acting superintendent in Mashpee, where students were dismissed early after the threat came in around 1:40 p.m., said authorities are “hopeful that no further disruptions occur and that no additional cancellations will be necessary when our students and staff return to school next week.”
All after-school and evening events in Mashpee were canceled Friday.
The school district “will continue working closely with the Mashpee Police Department to ensure the safety of our students and staff,” DeBoer wrote in an e-mail.
Attempts to reach superintendents of the other school districts regarding plans for Tuesday were unsuccessful.
In addition to state and federal law enforcement agencies, Governor Charlie Baker’s office was also monitoring the situation heading into the long weekend. Schools in the Commonwealth will be closed Monday in observance of Martin Luther King Jr. Day.
“The Massachusetts State Police are investigating these incidents at this time and the Governor’s Office will remain in close communication with public safety officials,” said Billy Pitman, a spokesman for Baker, in an e-mail.
Maryland State Police said a threat was received Friday by the Worcester County, Md., school system and referred further questions to the county sheriff’s office.
In a statement, the Worcester sheriff’s office said a bomb threat was called into Stephen Decatur High School shortly after 12:20 p.m., and that a second threat was later phoned in “targeting all Worcester County Schools.”
Those schools were evacuated, and investigators found no explosive devices, the statement said.
The sheriff’s office did not say whether the threats in Maryland were related to the calls in Massachusetts, and a sheriff’s dispatcher said no one was available for further comment.
Friday’s incident in Maryland came one day after the Worcester sheriff’s office announced that an unnamed juvenile had been arrested for allegedly making an earlier bomb threat Wednesday morning, also at Stephen Decatur High School.
Globe correspondents J.D. Capelouto and Mina Corpuz contributed to this report.