Two teenagers were arrested on Monday in South Pasadena, California, for allegedly planning a mass shooting at their school. The students had planned to “kill three staff members and as many students as possible with firearms” at the South Pasadena High School.

The administration of the school, which is located about eight miles northeast of downtown Los Angeles, informed police after they became aware of suspicious behavior last Thursday, following which authorities and police officials kept up a constant surveillance on the two boys. The arrests were made after police officials searched the house of the teens and gathered evidence about their mass-shooting plans.

"Enough evidence was discovered, and based on that evidence the two students were arrested," the South Pasadena Police Department said, in a statement. “One of the students was arrested without incident. The second student resisted arrest and officers had to force entry into his residence. He was captured in the home as he tried to run away from the arresting officers.”

Authorities reportedly said that no weapons were found from either of the students, but added that the two suspects were trying to acquire them to proceed with their shooting spree.

“They were researching weapons and how to fire and assemble them,” police Sgt. Robert Bartl told the Pasadena Star-News.

Details about the two teenagers' plans were not revealed but reports said that authorities will provide more information on the case at a news conference on Tuesday.

“The police have the situation under control and there is currently no threat to students or employees,” South Pasadena Board of Education Superintendent Geoff Yantz said Monday, according to CBS Local Los Angeles. “Psychologists and counselors will be available at the high school to provide support to our students and employees. The School Board and I appreciate the immediate response by the South Pasadena Police Department, and school will begin on as planned.”

According to reports, classes at the high school, which currently has just over 1,500 students, will resume from Thursday.

“School doesn’t start until Thursday and that was one of our goals — to make sure the investigation was moving very quick,” Bartl said, according to Pasadena Star-News. “(We) had detectives working nonstop the last four-to-five days since we received the actual report so that we could put a stop to this prior to school starting.”

Bartl also reportedly said that while investigators have spoken with the teachers who were on the students' hit list, they are yet to speak with the two arrested teenagers.

“This is a prime example of school officials recognizing suspicious behavior. It was this information that helped prevent a horrific tragedy,” according to police Sgt. Brian Solinsky.