A strong earthquake rattled the U.S. East Coast Tuesday, sending tremors as far as Canada, shaking the nation's capital and scaring thousands of office workers who fled onto the streets.

There were no reports of major damage or injuries from the 5.8 magnitude quake, which was centered in Mineral, Virginia.

It was the largest quake in Virginia since 1897 and struck at a shallow depth, increasing its potency.

Two nuclear reactors at the North Anna power plant in Virginia shut down after the plant lost power, but the company that runs them said there was no major damage. The reactors will remain shut until they can be safely restarted. [ID:nN1E77M1TW]

The Pentagon, White House and U.S. Capitol were evacuated in Washington, and thousands of alarmed workers scurried into the streets up and down the East Coast as the lunchtime quake sent items crashing to the floor from store and office shelves.

``We were rocking,'' said Larry Beach, who works at the U.S Agency for International Development in downtown Washington, 83 miles from the quake's epicenter. ``It was definitely significant.'' Federal workers in Washington were sent home early.

Washington's National Cathedral, host to state funerals and memorial services for many U.S. presidents, suffered damage with three spires in the central tower breaking off.

The U.S. East Coast does not normally feel quakes as strong as Tuesday's. The U.S. Geological Survey said the quake was of 5.8 magnitude, downgrading an earlier estimate if 5.9.

Earthquakes of magnitude 5.5 to 6 can cause damage to buildings and other structures.

As if a rare strong earthquake were not enough, the East Coast was also on alert for powerful Hurricane Irene which was heading up from the Caribbean and could hit at the weekend.

The quake made chandeliers sway in the U.S. Capitol and the floor of the U.S. Senate shook before staff headed for the doors. The U.S. Congress is in recess so most members were away.

``I thought at first somebody was shaking my chair and then I thought maybe it was a bomb,'' said Senate aide Wendy Oscarson-Kirchner.

NEW YORK EVACUATIONS

Phone service was disrupted throughout the region as network congestion prevented cellphone users from making calls.

In New York, the tremors prompted evacuations of courthouses, City Hall and halted work at the World Trade Center construction site.

``What a spooky, strange feeling,'' said Billy Simeonidis, the owner of BareBurger in Brooklyn. ``You just don't have any control. I don't know how they do it on the West Coast.''

Control towers at John F. Kennedy International Airport in New York City and Newark Liberty Airport in New Jersey were also evacuated, and flights were grounded briefly in Washington, Philadelphia and New York.

The quake was felt as far away as Toronto. Buildings in Boston were evacuated, and some people who experienced swaying offices said they felt their stomachs turn.

``I thought I was dizzy and I needed to drink more water,'' said Heather Kennaway, a manager at Sportello, a local restaurant, who was unaware of the earthquake.

A wave of saturation TV coverage of a quake that caused little or no damage on the East Coast drew smirks of amused disbelief from seismic-savvy Californians watching the news.

``East Coasters freak out, West Coasters roll their eyes,'' read one headline accompanying a story about Twitter reactions on the Hollywood news website The Wrap.com.

Tremors reached Martha's Vineyard as President Barack Obama was playing golf on his summer vacation. It was unclear if Obama felt the quake.

Vacationers at the Hamptons, the upscale resort on eastern Long Island, felt the earth shake. Many grabbed their cell phones to make calls, while several began asking aloud whether a tsunami -- a huge wave created by an underwater quake -- was headed their way.

In addition to the Virginia earthquake, there were nine tremors in the area immediately around Cokedale, Colorado, near the border of New Mexico, the largest of which was a 5.3 magnitude.