WHITBY, Ont. - Police investigating a house explosion east of Toronto say they believe the blast occurred when butane was being used to make cannabis oil.

The explosion took place around 3:30 p.m. on Wednesday in Whitby, Ont., leaving three men with non life-threatening injuries.

Local television footage shows one wall partially collapsed and several windows blown out.

Jody Cormier, 48, of Whitby, has been charged with arson with disregard for human life, criminal negligence and altering cannabis with an organic solvent.

Police say Cormier was released on a promise to appear in court.

They say engineers are now working to determine the safety of the house.