Toronto police say they responded to a threatening call near the intersection of Mount Pleasant Road and Elm Avenue on June 13.
Officers determined that the threat was unfounded. No one was injured, police said.
A 15-year-old girl was arrested on Monday and charged with death threats, public mischief and passing on information he knows to be false with the intent to alarm someone.
Then, in Ajax, a 15-year-old boy was charged with uttering threats against Notre Dame Catholic Secondary School.
Durham Region Police were called to the school on Harwood Avenue North at around 2.35pm on Monday for a threat of violence.
The school was briefly placed in lockdown and a student was arrested at the scene.
The teenager was charged with mischief and uttering threats.
Police want to remind the public that threats to schools are taken very seriouslyDurham Regional Police said in a statement.
Neither of the two teenagers can be identified due to their age.