Police have arrested four high school students in Northern California in connection with plotting killings of fellow students and teachers. The arrest comes just days after a mass shooting on a community college campus in rural Oregon.

The four, all students at Summerville High School in Tuolumne, Calif., "were going to come on campus and shoot and kill as many people as possible at the campus," Sheriff James W. Mele of Tuolumne County said at a news conference on Saturday.

Sheriff Mele did not reveal the identity of the students but said all were male juveniles. Tuolumne is about 120 miles east of San Francisco.

Mele added that the investigators were yet to find any clear motive for the planned attack, but he said that "the suspects" plans were very detailed in nature and included names of would-be victims, locations and methods in which the plan was to be carried out." The students planned to open fire during an event at school, he said, and "were in the process of trying to obtain these weapons."

The plot was foiled by the police on Wednesday after some students alerted a teacher after they overheard three of the four discussing a plan to open fire on the school.

The teacher informed the school administrators, who immediately called the police, said Robert Griffith, the superintendent of the Summerville Union High School District.

The fourth suspect was identified during the investigation. "Within two to three minutes, those administrators got up out of their seat, recognizing the severity of the information that they received, and were in the classroom pulling those students out," Griffith said at the news conference.