A propane explosion at an oilfield site southwest of Edson Monday morning injured a dozen people.

The blast occurred just before noon at the Husky Energy well near Robb, Alta.

A man in his 20's was airlifted to hospital by Stars, and arrived at the University of Alberta Hospital in critical condition. A second victim was flown to hospital with serious injuries. The other ten people who suffered burns are being treated at the hospital in Edson.

Occupational Health and Safety officials have been advised of the incident.

"Our understanding right now from an Occupational Health and Safety prospective is that propane was being used at his oilsite, quite a common procedure that happens and that at some point an explosion happened. Clearly something went wrong," said Barrie Harrison, spokesperson for Occupational Health and Safety.

Police say the Edson fire department attended the scene and managed to extinguish the fire.