Four students studying at a California high school were arrested Friday after the police found a detailed mass shooting plan that included the names of the target victims.

At a press conference on Saturday, Tuolumne County Sheriff James Mele did not reveal the names of the all-male suspects but said they were students at Summerville High School.

"Detectives located evidence verifying a plot to shoot staff and students at Summerville High School," Mele said, according to NBC News. "The suspects' plan was very detailed in nature and included names of would-be victims, locations and the methods in which the plan was to be carried out."

The plan was revealed when Summerville students heard the suspects talking about the planned shooting last week and informed school authorities, which, in turn, contacted the police.

He said the "common denominator" of the target victims is their being students of Summerville and the suspects were in the process of getting weapons.

"I have no idea why somebody or a group of individuals would want to do this," said Mele, adding that "cyber-bullying is a problem in our society. I think children today have a hard time trying to understand what is reality and what is fiction," he said.

Assistant District Attorney Eric Hovatter said they will decide what charges to file against the suspects, who are scheduled to be arraigned as juveniles, according to The Modesto Bee.

He said the plot is reminiscent of the Columbine and Sandy Hook shootings.

"It is clear from past history such as Columbine and Sandy Hook, as well as other recent events in Oregon, that children are willing and capable of planning and carrying out acts of violence against fellow students and teachers on school grounds," Havatter said. "While it is easy to say that would never happen in Tuolumne County, the public and local law enforcement must remain vigilant as they did here. That the suspects are young does not minimise the gravity of the conduct nor the potential for great harm to many people."

The Summerville Union High School District has 720 students in various campuses. Parents were informed about the incident.

Sonora resident Kristin Wilson's daughter is a sophomore at Summerville High.

"You watch it on the news all the time, it happens all the time. But you don't think it will happen to your daughter. When it becomes this really it hits a part of your heart you never want to be touched," she said.