A 17-year-old boy accused of detonating two pipe bombs at a Northern California high school while armed with a chain saw, sword and explosives appeared in court Wednesday on charges of trying to murder two faculty members.

A former student at Hillsdale High School in San Mateo did not enter a plea to charges that included exploding or attempting to explode bombs in a school to terrorize others and possession of dangerous weapons — the sword and chain saw.

No one was injured in the attack, which quickly ended when faculty members wrestled the attacker to the ground. Prosecutors said they would try the teen as an adult for Monday's attack.

"He planned this elaborately," said Deputy District Attorney Karen Guidotti, adding that the teen could spend the rest of his life in prison if convicted of the attempted murder charges.

The prosecutor declined to discuss why the teen allegedly wanted to kill security aide Jana Torres and chemistry teacher Meghan Spalding.

"We believe he had intent to harm them," Guidotti said. "We believe they were intended targets."

Police Chief Susan Manheimer has said investigators believe the teen planned to carry out a "cold-blooded plot of execution" on students and teachers because he was angry with the school administration.

Principal Jeff Gilbert said the teen hadn't been a student at the school for more than a year.

Guidotti said the teen was being prosecuted as an adult because of the serious nature of the alleged crimes and because he was about eight months from his 18th birthday.

The teen appeared in a packed courtroom with his parents and sister in the front row. He stood behind a thick glass partition wearing a lime-green T-shirt with his right arm heavy bandaged.

Guidotti believed he was injured when he was wrestled down by faculty members at the school.

San Mateo Superior Court Judge Mark Forcum granted the prosecutor's request that the teen be held in Juvenile Hall without bail until his next court date on Sept. 3.

Meanwhile, classes resumed at the school for the first time since Monday's incident.

Students and staff members participated an assembly where those who took down the attacker received a standing ovation.

The morning was spent discussing the incident, with classes resuming in the afternoon. Counselors also talked to individual students.

"They're trying to get back to normal," said Kirk Black, associate superintendent for the San Mateo Union High School District. "I think everybody is really coming together. They're relieved that no one was hurt and that school is back in session."