Two strong earthquakes -- the first measuring 6.6 magnitude, the second 6.8 -- struck in quick succession off Canada's west coast late Sunday, the US Geological Survey said.
The epicenter of the first tremor, at 10:39pm (0549 GMT Monday), was located about 135 miles (218 kilometers) southwest of Port Hardy -- a small municipality on the northeastern tip of British Columbia's Vancouver Island.
The second stronger quake occurred 122 miles southwest of the same town more than half an hour later, at 11:16pm.
There were no initial reports of damage or injuries, and no tsunami warnings were issued.
The region is located near the Cascadia subduction zone, a mammoth fault line that lies offshore, stretching from northern Vancouver Island to Northern California in the United States.