Investigators say a search of a garage where an explosion happened on Friday in Barrie has led to the discovery of hash and marijuana resin oil.

In a news release issued on Monday, Barrie police say searches of the 59 Collete Cres. home turned up cannabis marijuana, cannabis resin, also known as hash, and cannabis oil. Butane canisters were also found at the scene.

Investigators previously suspected a butane canister was being used in the extraction of marijuana resin when the explosion occurred. The Ontario Fire Marshal’s office has not yet determined a cause.

“Quite often people will grind up the rest of the leaves from the plant, and then they use the butane or some other solvent to extract the THC out of that part of the plant,” says Det. Sgt. Peter Dewsnap. “You're involved in a process, where you're using a flammable gas or liquid, so the very process is inherently dangerous.”

Police and fire investigators released the scene late Sunday afternoon, after spending the day sifting through debris and collecting evidence. The OFM has since sent samples for testing and are awaiting results.

In total, police say four people were in the garage, while eight children and two adults were in the house when the explosion happened. The children range in age between three-weeks-old and 15-years-old. Eleven people were taken to hospital, two of which are in critical condition – six others have been released.

This isn’t the first time an explosion like this has happened in Barrie. In 2004, there was an explosion at a home in the north end of the city. In that instance police say someone was trying to make hash oil and butane was being used.

As a result of what police found at the home on Collete Crescent, officers say criminal charges could be laid.