DAWSON CREEK, B.C. - Police are treading carefully in their investigation of a suspicious explosion at an EnCana natural gas pipeline in northeastern B.C.

RCMP Cpl. Dan Moskaluk says officers have to make sure the area is safe to enter before they can go in and determine if the blast was human-caused or criminally motivated.

The rupture in a wellhead was discovered yesterday and an EnCana spokeswoman says the damage suggests an explosion took place.

The blast happened in a remote area outside of Pouce Coupe, just a few kilometres from the Alberta boundary.

There have been four acts of sabotage aimed at EnCana pipelines in British Columbia in the last nine months.

There were three explosions last October involving pipelines or wellheads carrying sour gas, and a metering shed was destroyed by a blast in January.