A 17-year-old boy has been arrested for allegedly plotting an attack on a Toronto high school on the 27th anniversary of the massacre at Ecole Polytechnique in Montreal, one of the worst mass murders in Canadian history.

Toronto Police say the teenager, who cannot be identified due to his age, was arrested Tuesday morning after police conducted a search warrant in his home. Investigators allegedly discovered a number of weapons, including a machete, a hatchet, two swords, four knives, and arrows for a bow-and-arrow.

Police also seized some articles of clothing that investigators allege the teenager planned to use to hide the weapons. Some computer equipment was also seized.

Police say they learned of the alleged plot on Dec. 1 after someone from the United States alerted Toronto police to a threatening blog post allegedly written by the suspect.

“He had mentioned in his threat about the day of the (Montreal) massacre … and we do believe that was the day it was going to be executed,” Det. Len Nicholson told CP24 in an interview on Wednesday.

Upon further investigation, police learned that the alleged threatening post was made on a Toronto District School Board computer server, and they identified the alleged target as Oakwood Collegiate Institute, a Toronto public high school.

The suspect was a student at a Toronto high school, a Toronto District School Board spokesperson confirmed. They did not say which school the teen attended.

Nicholson said police haven’t pinpointed a suspected motive in the alleged plot and that the suspect did not provide those details to police.

“He did not. He had spoken to a lawyer,” Nicholson said.

In a press release, police say that “some sort of attack” was to take place on the Tuesday, on “the 27th anniversary of the massacre at Ecole Polytechnique in Montreal.”

In 1989, 14 women at the Montreal school were shot to death by a gunman who blamed “feminists” for ruining his life. The mass shooting is one of the deadliest attacks in Canadian history.

Nicholson said police believe that the suspect was plotting the alleged attack on his own.

The high school’s principal sent a letter home with students Wednesday explaining the police presence at Oakwood Collegiate on Tuesday.

“They were here to investigate a reported threat made toward the school,” principal Steve Yee wrote. “Earlier that day, officers contacted me to advise that they had arrested a person overnight in relation to that threat. As a result, it was not necessary to disrupt regular school routines.”

The 17-year-old suspect appeared in court on Tuesday. He has been charged with uttering threats of bodily harm and uttering threats of death.