A 6.6-magnitude earthquake struck last night shortly after 8 p.m. PT, with the epicentre located 40 kilometres southwest of Port Alice, according to the Pacific Tsunami Information Centre.

There were no initial reports of damage or injury.

The earthquake was initially reported at 6.7 magnitude, but the U.S. Geological Survey's National Earthquake Information Centre later changed the scale of the quake to 6.6.

The epicentre had a depth of 11 kilometres, according to USGS. The Pacific Tsunami Information Centre initially reported it to be 22 kilometres.

Although the earthquake was powerful enough to generate a local tsunami, the risk of one was quickly ruled out.

'The windows started rattling'

People from as far away as Kelowna, B.C., about 575 kilometres from the epicentre, reported feeling buildings sway. Within an hour of the quake, more than 400 people also reported feeling it to the USGS.

Some residents in highrises said they felt their building sway, including Marjorie Blair, who was in her 12th-storey apartment in Burnaby when it hit.

"I looked up and my first instinct is always to look at the chandelier when something happens, and it is rocking I am telling you," said Blair.

Earthquake map

The 6.6 -magnitude earthquake struck Wednesday 40 kilometres southwest of Port Alice. It was initially reported at 6.7 magnitude, but the USGS National Earthquake Information Centre later changed the scale of the quake to 6.6. (CBC)

"Then I heard the clicks, the clicks on the glass, and there are the rods on the curtains and they were hitting the glass."

In Port Hardy, about 89 kilometres northeast of the earthquake's epicentre, Deputy Fire Chief Brent Borg said there happened to be a meeting at the fire hall when the earthquake struck.

"The windows started rattling, the walls started rattling and one of the lieutenants says, 'Did we just have an earthquake?'" he told CBC News.

Borg said one of the local firefighters phoned in to say he had some pictures rattle off his mantle. He said no local warnings were issued, and firefighters did not have to respond to any emergencies.

"It was a pretty minor shake. It was less than 10 seconds."

Port Hardy Mayor Bev Parnham told The Canadian Press that although the quake was short, it was strong.

Pamela Shea was working a late shift at Port Hardy's Airport Inn when she felt the quake, which she said lasted between 10 and 12 seconds.

USGS shake map

U.S. Geological Survey map shows the area of shaking in yellow surrounding the epicentre of Wednesday night's earthquake. (USGS)

"My chair was rolling back and forth, the bottles were rattling," she told CP. "I've lived here 37 years and I've never felt anything like it."

The earthquake was followed by three aftershocks, one of magnitude 5 and the next two both at magnitude 4.2. The second was initially reported at a magnitude 4.

The USGS says aftershocks of this size are normal for a quake of this magnitude.

Earthquakes are common off the province's coast, where the Juan de Fuca tectonic plate meets the Pacific tectonic plate. However, few earthquakes are large enough to be felt by humans.

The most recent large earthquake in B.C. was in October 2012. A magnitude 7.7 quake shook the northern B.C. Haida Gwaii Islands.

With files from The Canadian Press