An unusually strong earthquake sent shock waves far beyond its Virginia epicentre on Tuesday, rattling residents all over the U.S. Eastern Seaboard and Canada.

The U.S. Geological Survey put the quake's magnitude at 5.8. It was centred near Mineral, Va., about 135 kilometres southwest of Washington, D.C. After several revisions, the U.S.G.S. placed the quake's depth at six kilometres.

There were no reports of serious injuries or deaths but a fire department spokesman in Washington said there were reports of minor injuries.

Some damage was reported to buildings in the U.S. capital. A spokesman for Washington's National Cathedral says at least three of the four stone pinnacles on the central tower had fallen off and the central tower looked like it was leaning.

Several airports in New York, Philadelphia and the Washington area briefly suspended flights.

In the Washington, D.C., area, many major buildings were evacuated. In nearby Virginia, people ran through the corridors of the Pentagon amid shouts of "Evacuate! Evacuate!"

"I thought it was a big truck going down the street at first until the building started to sway," said CBC associate producer Caroline Laurin, who works in the CBC's Washington bureau.

"Then we all laughed nervously."

Two nuclear reactors near the epicentre in Virginia were automatically taken off line. No damage was reported there.

U.S. President Barack Obama was starting a round of golf in Martha's Vineyard, Mass., when the quake struck. He apparently didn't notice it. The White House said he held a conference call with administration officials and was assured there was no major damage.

The quake was also felt in New York, Maryland, North Carolina, Ohio, Georgia and north into Canada.

In New York City, workers in the Empire State Building walked down dozens of flights of stairs. "I thought we'd been hit by an airplane," said one worker, Marty Weisner.

People from across the U.S. Eastern Seaboard and from Ontario to New Brunswick headed to their phones and their Twitter accounts to say they felt the ground move when the temblor struck at 1:51 p.m. ET.

Office workers gather on the sidewalk in downtown Washington, D.C., moments after a 5.8 magnitude earthquake struck on Tuesday. (J. Scott Applewhite/Associated Press)

In Toronto, CBC provincial affairs reporter Mike Crawley said he felt the walls of the Ontario legislature shake.

“I live on the top floor of my building and two of my chandeliers and two big mirrors in my living room and dining room were shaking,” wrote Steve Smythe of London, Ont.

A pair of government buildings in downtown Sudbury, Ont., were evacuated after they began shaking. City officials say they were cleared out in order to check for any damage. Windsor, Ont., also felt a jolt and city hall was evacuated.

Other viewers called and tweeted the CBC, reporting that they felt the earth shake in and around Ottawa and downtown Montreal.

Numerous buildings in downtown Fredericton have been evacuated. That included various government buildings and New Brunswick Power.

There were no reports of injuries or damage in Canada.

The quake quickly became a trending topic on Twitter, leading some to poke fun at all the fuss. Many people retweeted a picture of a patio set with one of its plastic chairs flipped on its back. Attached to it was the following message: "Thanks to all of you for your kind words of support, as we look to recover from the devastation of today's quake."

Biggest East Coast quake since 1944

If this earthquake's magnitude remains at 5.8, it would almost rival the largest one ever recorded in Virginia — a 5.9 quake that shook the state in 1897. It would match a 5.8 quake that rattled through New York in 1944. The biggest quake to ever hit the U.S. East Coast took place in South Carolina back in 1886. It had a magnitude of 7.3.

Quakes of this power are much more common in the western U.S. But when they happen on the East Coast, they're felt over a wider area as the ground is older and more intact.

"The waves are able to reverberate and travel pretty happily out for miles," said U.S. Geological Survey seismologist Susan Hough.

With files from The Associated Press