CLINTON TOWNSHIP, Mich. -- A 17-year-old Michigan teenager is accused of plotting a Columbine-like attack on a high school after police say the plan was foiled by a man thousands of miles away.

Police said Andrew Osantowski (pictured, right) made threats over the Internet to bomb Chippewa Valley High School in Clinton Township, Mich. Investigators executed a search warrant on the boy's home and a neighbor's home Thursday night.

"Investigators then took into custody the student and his father," said Clinton Township police Chief Al Ernst. "Our investigators found what appears to be the student planning an attack on the school and our police officers."

A neighbor was also arrested.

Police reportedly learned of the plan by a teenage girl and her father who live in Washington state. The girl was chatting with Osantowski online when her father -- a police officer -- noticed the content. He then alerted police in Michigan about the online chat, WDIV-TV reported.

SCHOOL SCARE Police Display Weapons, Items Seized From Student's Home Former Student Expresses Concern

Mills said there was no date for a planned attack, but it is believed Osantowski was plotting something "in the near future." He said the boy was "angry" at everyone and did not name a particular race of students.

Someone gave the Osantowski verbal assistance on how to make a bomb and provided him with Web pages to do it, according to Capt. Douglas Mills.

Items found during the searches include blueprints stolen from the high school, an AK-47 and other weapons, ammunition, 15 pipe bombs and instructional bomb-making videos and materials, reported WDIV-TV in Detroit. Police displayed some of the items, including tools stolen from local construction sites, in a Friday press conference.

The school was closed Thursday afternoon for the investigation and games were canceled Thursday evening. Nothing was found during a search of the school, and classes resumed Friday morning.

"The school has been very active in taking precautions to ensure it is safe. We believe the school is safe and the community is safe," said Ernst.

Parents will be informed of the investigation through a letter from school officials.

"It's scary," said former student Adam Smalley. "I know kids that go here. I have friends who go here. I worry about them."

School officials said the 17-year-old attended De La Salle High School in Warren, Mich., in September 2002, where he spent his freshman year and a few weeks as a sophomore. Police said they have not found any evidence that other students were involved.