School leaders canceled classes in Falmouth and Yarmouth Friday after police learned of an online threat against the schools that they later determined was not credible.

In an email to parents Friday morning, Yarmouth Superintendent Andrew Dolloff said he received a call from the Yarmouth Police Department that an online threat had been made against the schools.

The threat was posted on a social media network and mentioned a shooting at both towns’ schools, Falmouth Police Chief John Kilbride said.

By late afternoon, Kilbride said that FBI agents and local police determined that the threat was not credible, but he declined to release details about how authorities debunked the message.

No one has been charged, and he said that bringing a case against the person or people involved may prove difficult.

“We don’t think this was generated locally,” Kilbride said.

Though Maine experienced a string of school closures this week, including 10 successive threats called in on Tuesday morning that caused widespread confusion and anxiety as parents rushed to schools across the state, Kilbride said federal officials told him that such cases occur daily across the country.

“Talking with my federal partners, I hear these events play out across the country, all day long,” he said.

Kilbride suspects a copycat effect is in play, but there is no data to support it.

“There are individuals who see this and see fear instilled like what you saw Tuesday and like that and want to continue that,” he said. “I think that’s true in any society – there are people who like chaos.”