Map locates a violent earthquake measuring 7.7 which jolted British Columbia's north-central coast Saturday night, frightening residents and forcing many to temporarily leave their homes for higher ground ahead of a possible tsunami.THE CANADIAN PRESS/Sean Vokey

VANCOUVER - Residents on the north-central coast of British Columbia felt the ground roll and watched hydro poles sway as a powerful 7.7 magnitude earthquake jolted the coast.

The quake set off a tsunami warning for the North Coast and Haida Gwaii islands and parts of the central coast, including Bella Bella, Bella Coola and Shearwater.

The provincial emergency co-ordination centre issued a bulletin saying it's believed that a low level tsunami could impact marinas and other coastal infrastructure or create strong currents in harbours and coastal areas.

Other areas of the B.C. coast, including the northern end of Vancouver Island and the southern tip of the Island from Jordan River to Greater Victoria, including the Saanich Peninsula, have been put under advisory that there could be a tsunami.

Residents in those areas have been told to move to higher ground and not return until they are given the all clear.

Bella Coola resident Carsten Ginsburg said the quake lasted for about 40 seconds.

"It shook everything. The electricity went out, the power lines were swinging all over the place and stuff was falling off the shelves."

Ginsburg said he ran home as quickly as he could to see if there was a tsunami warning.

"Which of course there was," he added.

Ginsburg owns the Float House Inn on the public wharf in Bella Coola and had about six customers celebrating a birthday party.

They all evacuated to about 35 metres above sea level.

"I'm assuming that's it OK," he said laughing. "I'm keeping my fingers crossed."

Residents rushed out of their homes in Tofino when the tsunami sirens sounded, but they were allowed to return about two hours after the quake.

Yvett Drews, a resident of Tofino, said she and dozens of others had gathered at the local elementary school where they were told by police that they could return home.

But while on the way home, Drews said she heard the tsunami sirens go off again.

"Well that just freaked me out, hearing the siren and the voice," she said.

The quake was felt on Vancouver Island, the Haida Gwaii area, Prince Rupert, Quesnel and Houston, and even through Metro Vancouver, but so far there have been no reports of damage.

It struck just after eight o'clock local time, its epicentre 17 kilometres below ground some 200 kilometres south-southwest of Prince Rupert.

It was quickly followed by several aftershocks above magnitude five.

News from © The Canadian Press, 2012