PORTLAND — Portland and Gorham public schools will have an increased police presence through the rest of the week, after an alleged Facebook message was posted threatening harm to schools in Cumberland and York counties.

Portland School Superintendent Emmanuel Caulk issued a press release Wednesday night saying the Portland Police Department had met with high school principals about the message.

“All of our schools have emergency plans in place and our staff members are familiar with those plans,” the release said. “Deering and Portland High Schools will continue to have full-time police officers on site to provide assistance, and an officer will be provided on December 21 to the Casco Bay High School and Portland Arts and Technology High School location. In addition, the police will continue their increased patrols for this week, in the aftermath of the Newtown, Connecticut incident. We take seriously any and all threats and work with police to investigate them appropriately.”

The release said the message did not refer specifically to Portland Public Schools and there was no indication the threat was real, but the district was “taking every precaution to protect our students and staff.”

Gorham School Superintendent Ted Sharp said in a letter to parents that was posted on the Gorham School Department’s website that school and law enforcement officials met Wednesday morning “to develop a plan to further deter any aggressive act against (Gorham High School).”

State police spokesman Steve McCausland confirmed Wednesday evening that state police are looking into the origin of the Facebook message.

Sharp said police will be present at the schools on Friday, which he also noted is the date of the Mayan calendar’s supposed apocalypse.

It was not clear whether other schools also plan to respond or if the threat was considered limited to  certain communities. Police provided no details about the threat. Reached by phone Wednesday afternoon, Sharp said, “I don’t have time” to explain details about the threat or how the Facebook message surfaced.

In his letter to parents, Sharp said law enforcement officials are still trying to determine the origin and authenticity of the threat – and given the “fragile environment” following the Newtown, Conn. shootings, he understands parents will be concerned. Sharp said the Gorham schools are taking the necessary steps to ensure everyone’s safety, but “it would not be prudent of us to release those details.”

The letter from Sharp said, “It has come to our attention that there is a message on Facebook, the origin of which at this time has not been determined, suggesting that on Friday, Dec. 21, high schools in Cumberland and York County will be the target of someone intending to do harm.

“While threats like this are, unfortunately, not uncommon in our society, please know that we take each one seriously. … We will as stated, intensify our vigilance at each school.”

A Cumberland County dispatcher directed questions to Gorham police, who didn’t answer the phone Wednesday evening.