Updated

A 15-year-old boy is being held in a psychiatric hospital after he stockpiled gasoline, propane, fuses and a machete for a planned attack at a New York school on the anniversary of the Columbine High School killings, police sid.

The boy, whose name was withheld, was arrested Monday evening after police searched his home in Monroe, 45 miles northwest of New York City.

Police found 16-ounce bottles of gasoline, a torch, a machete, a black trench coat, two computers, three propane tanks and several other electronic devices, MyFoxNY.com reported.

Police say he told them he planned to attack the Monroe-Woodbury High School on April 20 and was looking to buy an assault rifle.

Police say the boy recently transferred to another school and harbored grudges against former classmates. Police say it appears he acted alone.

Monroe-Woodbury Superintendent Joseph DiLorenzo said the willingness of students to come forward with information averted any threat to the district.

The Associated Press contributed to this report.

Click here to read more on this story from MyFoxNY.com.