Email threats sent to dozens of schools around the state Thursday prompted some Maine schools to initiate lockdowns and notify parents before police determined them to be hoaxes.

Schools in Kennebunk, Kennebunkport and Arundel were locked down Thursday morning, but returned to normal operations by early afternoon, according to letters sent to parents.

“The nature of the threat that was received was a bomb threat, which was widely distributed to at least 70 schools across the state, according to law enforcement,” Terri Cooper, RSU 21 superintendent, wrote in an email to parents on Thursday. “Though police did not believe the threat to be credible, we acted out of an abundance of caution to ensure the safety of everyone in our schools.”

Police checked the schools during the “hold in place” order on Thursday morning, and after determining the schools were safe, the schools reopened shortly after noon, according to Cooper.

The Maine State Police said about 60 Maine schools were targeted by the threats, which also targeted schools nationwide. The threats were deemed to be hoaxes, police said.