Durham Police say a fifth person, a female, has been found dead following a shooting at a home in Oshawa.
Police responded to a home on Parklane Avenue near King Street East and Harmony Road South around 1:20 a.m. Friday after reports of multiple shots fired.
They initially found the bodies of two men and two young teens, before later discovering the female.
Police believe the shooter is among the dead.
A sixth person, a woman, is in hospital with non-life threatening injuries.
Neighbours tell NEWSTALK 1010 that the home belongs to a family with two young teens and two university-aged siblings.
They say the parents are local teachers.
A pickup truck at the scene, with Manitoba licence plates, is said to be part of the investigation. Neighbours say they don't recognize it.
It's not clear what led to the shooting.
A Durham Police spokesperson told reporters at the scene, when officers originally arrived on scene, they heard gunshots and a commotion inside the house, but didn't immediately go inside. Instead, they waited for the tactical team to show up.
How much time elapsed before that happened, we don't yet know.
Police were forced to clear out of the home during the removal of the bodies, when a suspicious device was found inside the home.
It's unclear if the device is, in fact, an explosive.