ORLEANS COUNTY, NY (AP) – Three middle-school students have been charged with plotting to kill multiple people at their upstate New York school with guns and explosives, authorities said Friday.

The Albion Middle School students were arrested Thursday after investigators determined a threat that started on an online gaming app was credible, Albion Police Chief Roland Nenni said by phone.

The students, all under 16 years old, are charged as juveniles with conspiracy to commit multiple murders, he said. Their names and ages weren’t released.

“They had a date set,” Nenni said. “The plan was to use explosives, incendiary devices and firearms to kill and injure students and staff in the Albion Middle School.”

He said officers recovered electronics and some legally possessed firearms during an investigation that was initiated after a student-on-student threat in the online gaming app Discord, on Monday.

Nenni did not disclose where police searched or where the weapons were located. But Orleans County District Attorney Joseph Cardone said via email that “there is no belief that the students had access to them and they were taken with cooperation of the students’ families.”

The threat also implied a broader danger, Nenni said, leading investigators to activate the school’s threat assessment team and involve multiple local, state and federal agencies. Authorities have not yet identified a possible motive, he said.

“We’re putting all the pieces together so we better understand it,” he said.

The chief declined to say when the alleged attack was to occur, adding that it was not imminent.

Gov. Andrew Cuomo on Friday praised school and police officials for their swift response.

“The plot was determined to be credible and the agencies worked quickly to investigate and identify the suspects,” Cuomo said in a statement.

In a letter to parents Wednesday, Superintendent Michael Bonnewell said the students were removed from school after officials learned they had shared “inappropriate and threatening messages and images” in the app.

“Reports note that the activity has continued in live conversations and at least one phone call,” Bonnewell wrote. “Some of these messages have been shared, repeated and commented on by others in conversations and throughout social media.”

A spokesman for Discord issued a statement saying the voice and messaging app takes immediate action when it becomes aware of harassment and illegal activity. It did not say what, if any action, was taken in the Albion case.

“We’re committed to ensuring that Discord is a positive and safe place for all our users,” wrote Sean Li, Discord director of trust and safety.

Albion, located between Rochester and Buffalo in western New York, has about 8,000 residents. About 400 students attend the middle school, according to the New York State Education Department website.

As reported by Vos Iz Neias