Police say Ontario’s Office of the Fire Marshal has declared a house explosion in Kitchener criminal in nature.
Waterloo Regional Police say the fire marshal made the call after two children and two adults were injured in an explosion inside a home in the city’s southwest.
Police say emergency crews were called to the house shortly before midnight on Wednesday.
They say two adults – a man and woman – were sent to an out-of-region hospital with serious injuries and remained there as of Thursday night.
Police say two children sent to hospital with minor injuries have since been released.
Police say the explosion came from inside the home and also caused significant structural damage to neighbouring units.