EDMONTON -- Six people were injured in an explosion at a campground site in northern Alberta Monday morning.

Emergency crews responded to the Marten River Campground at approximately 7 a.m. after an explosion involving a fifth wheel travel trailer, RCMP said.

Six people — all from the same family with ages ranging from six to 41 years — were treated for serious but non-life threatening injuries. They were first taken to a hospital in the area before they were relocated to Edmonton, police said.

The cause of the explosion is under investigation.

Marten River Campground is located approximately 300 kilometres north of Edmonton.