A 5.7-magnitude earthquake was detected in the Pacific Ocean near Vancouver Island on Friday evening.

It followed four smaller earthquakes to strike the same area in 24 hours.

A report from the U.S. Geological Survey says the epicentre of the 5.7-magnitude quake was 346 kilometres west of Campbell River.

The earthquake occurred less than a day after another 5.1-magnitude earthquake was recorded in the same region.

Natural Resources Canada says the earlier quake was the result of the seismically active area along the Cascadia subduction zone off Vancouver Island, where the squeezing of two plates of the earth's crust causes about 300 small temblors every year in southwestern B.C.