A magnitude 7.7 earthquake struck off the west coast of Canada and a tsunami warning was issued, authorities said, but there were no immediate reports of major damage.

The U.S. Geological Survey said the quake hit the Queen Charlotte Islands just after 8 p.m. local time Saturday at a depth of about 3 miles (5 kilometers) and was centered 96 miles (155 kilometers) south of Masset, British Columbia. It was one of the biggest earthquakes around Canada in decades and was felt across a wide area around British Columbia.

The National Weather Service issued a tsunami warning for coastal areas of British Columbia, southern Alaska and Hawaii. The first wave of the small tsunami, about 4 inches (101.6 millimeters), hit the southeast Alaska coastal community of Craig.

Dennis Sinnott of the Canadian Institute of Ocean Science said a 69 centimeter (27 inch) wave was recorded off Langara Island on the northeast tip of Haida Gwaii, formerly called the Queen Charlotte Islands. Another 55 centimeter (21 inch) wave hit Winter Harbour on the northeast coast of Vancouver Island.

"It appears to be settling down," he said. "It does not mean we won't get another small wave coming through."

The Pacific Tsunami Warning Center originally said there was no threat to the islands of Hawaii, but a warning was issued later Saturday and remains in effect until 7 p.m. Sunday. A small craft advisory is in effect until Sunday morning. The center says the first tsunami wave could hit the islands by about 10:30 p.m. local time.

The USGS said the 7.7 magnitude temblor shook the waters around British Columbia and was followed by a 5.8 magnitude aftershock several minutes later. Several other aftershocks were reported.

The U.S. Coast Guard in Alaska said it was trying to warn everyone with a boat on the water to prepare for a potential tsunami.

Lt. Bernard Auth of the Juneau Command Center said the Coast Guard was working with local authorities to alert people in coastal towns to take precautions.

The quake struck 25 miles (40 kilometers) south of Sandspit, British Columbia, on the Haida Gwaii archipelago, formerly known as the Queen Charlotte Islands. People in coastal areas were advised to move to higher ground.

Urs Thomas, operator of the Golden Spruce hotel in Port Clements said there was no warning before everything began moving inside and outside the hotel. He said it lasted about three minutes.

"It was a pretty good shock," Thomas, 59, said. "I looked at my boat outside. It was rocking. Everything was moving. My truck was moving."

After the initial jolt, Thomas began to check the hotel.

"The fixtures and everything were still swinging," he said. "I had some picture frames coming down."

Natural Resources Canada said in a statement that a major earthquake was felt across much of north and central British Columbia but that there were no immediate reports of damage. PrayForCanada became a worldwide trending topic on Twitter.

"I was sitting at my desk on my computer and everything just started to move. It was maybe 20 seconds," said Joan Girbav, manager of Pacific Inn in Prince Rupert, British Columbia. "It's very scary. I've lived here all my life and I've never felt that."

The quake was felt on the mainland in Prince Rupert, British Columbia, which is across the Hecate Strait from the islands.

"Everyone felt it here," said city recreation director Rudy Kelly, who was setting up an evacuation center for people from the city's low-lying areas. He said the work was in anticipation of a tsunami wave.

Prince Rupert resident Grainne Barthe said fire trucks had blocked access to the waterfront when she came out of a restaurant.

"Everything was moving. It was crazy," she said. "I've felt earthquakes before but this was the biggest. It was nerve wracking. I thought we should be going under a table."

Residents rushed out of their homes in Tofino, British Columbia on Vancouver Island 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.

Carsten Ginsburg, a resident on British Columbia's mainland in Bella Coola, 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 owns the Float House Inn on the public wharf in Bella Coola and had about six customers celebrating a birthday party.

Canada's largest earthquake since 1700 was an 8.1 magnitude quake on August 22, 1949 off the coast of British Columbia, according to the Canadian government's Natural Resources website. It occurred on the Queen Charlotte Fault in what the department called Canada's equivalent of the San Andreas Fault — the boundary between the Pacific and North American plates that runs underwater along the west coast of the Haida Gwaii.

Saturday's quake is the strongest in Canada since 1958 when a 7.9 magnitude quake struck along the B.C.-Alaska border about 500 kilometers (300 miles) northeast of Saturday's quake, according to the website.


Associated Press writer Mark Thiessen in Alaska contributed to this report.