In a Spy Kids-style scheme involving a circular saw, a getaway van and the disarming of motion detectors, seven teen-age boys tried to steal more than $100,000 in electronics from Old Mill Senior High School early Sunday, police said.

Officers arrested five 16- year-olds and one 15-year-old, all of whom are students at Old Mill. A seventh suspect, also 16 and an Old Mill student, has been identified, said Officer Charles Ravenell, a police spokesman.

The burglary attempt, which targeted science classrooms and had been planned for at least a month, according to police, was foiled when an officer who had arrived at the school about 3 a.m. to check out an alarm spotted a teen-ager walking away with a large, white duffel bag.

Because the suspects are juveniles, police did not identify them, saying only that they are residents of Odenton, Millersville, Glen Burnie, Severn and Crownsville.

At some point before the burglary, the teen-agers disabled several motion detectors at the school. Police were alerted to the break-in by a door alarm, Ravenell said.

Some of the teen-agers sneaked up to the school building on Patriot Lane in Millersville toting a portable circular saw, which they used to cut through a Plexiglas window to enter the school. Others remained outside the building to serve as lookouts, police said.

Once inside, the intruders smashed the glass doors to 11 classrooms and reached through to unlock them. In each classroom, the group faced a final barrier: solid wood doors on the equipment storage closets.

Again using the circular saw, the teen-agers cut holes in those doors and reached through to unlock them, gaining access to laptop computers, VCRs, overhead projectors, motherboards and other computer components, police said.

After gathering up the goods in large duffel bags, the teen-agers loaded a van, belonging to a relative of one of the suspects, that was parked on Phirne Road, on the other side of a wooded area by the school.

When one of the boys heard an officer walking through the snow and saw a police car in the parking lot, he dropped a duffel bag loaded with electronics and ran through a football practice field and into the woods.

As officers chased him, they spotted three others who then began to flee, police said. With the assistance of a police dog team, officers caught the four teen-agers. The others were arrested hours later. All were taken to the Eastern District police station.

"We haven't seen a burglary of this magnitude, especially at a school," Ravenell said. This year, there have been 55 burglaries at public and private schools, he said, up six from last year.

Most of the equipment stolen from Old Mill is back in the school, Principal Arlen Liverman said. Damage to the building is estimated at $5,000 to $10,000.

The boys each received juvenile citations charging them with second- and fourth-degree burglary, theft and destruction of property. They were released to the custody of their parents Sunday morning. Ravenell said police do not think any adults were involved.

Liverman, principal at Old Mill for the past six years, said he could not recall another burglary attempt of this magnitude at the school.

"Every year we seem to face something different," Liverman said. "This is very much new."

The principal said a brief announcement about the burglary attempt was made to the school's 2,347 students Monday morning. He also said he and other school administrators have begun to address ways to "beef up security and make school even more of a safe haven."

As an educator, Liverman said, he tries to encourage students to make good decisions but knows they will sometimes make bad choices.

"I try to put myself in the position where I'm not going to be surprised," Liverman said. "That way I'm not disappointed."