A 5.0-magnitude earthquake rocked Ontario, Quebec, and parts of the northeastern United States Wednesday afternoon, sending residents running into the streets.

While there were no immediate reports of damage or injuries in major city centres, the town of Gracefield, Que., which is very close to the quake's epicenter, declared a state of emergency after the quake damaged several buildings, including civic administration offices, a church and a grocery store.

"We declared a state of emergency because we don't know if our buildings are secure," Gracefield city councillor Michael Gainsford told CTV News Channel in telephone interview early Wednesday evening. "We closed down all public buildings because there's lots of damage to structures, there's cement cracks, there's pieces of chimney fallen down… ."

Gainsford said the building that sustained the most damage was the local church, where the chimney fell through the roof and many of the windows were cracked. Local residents reported seeing the steeple move as much as two inches, Gainsford said. Inspectors were up on aerial ladders surveying the damage.

None of the town's residents was injured, Gainsford said.

The quake hit shortly before 1:45 p.m. ET, and was felt in Montreal, Windsor, Ottawa and Toronto. The U.S. Geological Survey's National Earthquake Information Center received reports the quake was felt throughout New York State, Vermont, Massachusetts and Ohio.

The quake occurred at a depth of 16.4 kilometres, and its epicenter was about 56 kilometres north-northeast of Ottawa.

Earthquakes Canada spokesperson Janet Drysdale confirmed Wednesday evening the quake triggered a handful of aftershocks.

"There have been some aftershocks following this event; in the hour or two following it, there were approximately four or five" aftershocks of a magnitude greater than 2.5, Drysdale told the Canadian Press.

"We would expect some aftershocks, but they would diminish as time goes on."

Bruce Presgrave, a spokesperson with the Earthquake Information Center, said though quakes in the area are rare, the region is an active seismic zone.

"With typical building construction in North America, magnitude fives do not usually cause major damage," Presgrave told CTV.ca in a telephone interview from Colorado. "But if they are close to a city they can cause things like broken windows and things being knocked off shelves."

Earlier Tuesday, word broke that a bridge collapsed into a river north of Buckingham, Que., northeast of Ottawa. No one was injured. Other reports of damage included a gas main break on Parliament Hill, and sewer and water main breaks in North Bay, Ont.

Via Rail is also warning passengers travelling east of Kingston that they will experience delays due to the quake.

"Trains travelling east of Kingston will experience (a) 2.5 hour delay for infrastructure inspection due to (the) Quebec-Ontario earthquake," says a travel advisory on the company's website.

Tremor disrupts government work

In Ottawa, a live news conference on Parliament Hill was interrupted as reporters fled the room, which was clearly seen shaking on camera.

Environment Minister Jim Prentice was in the middle of an interview with BNN when "suddenly my chair was moving."

"So it was pretty significant, it was quite a shake. Fortunately I was at the end of the interview and we all vacated the building," Prentice said.

The quake disrupted a Senate session. Conservative Senator Lowell Murray said he and his colleagues were debating energy issues when chandeliers in the upper chamber began to sway.

"Initially we thought it might have been an airplane crashing into the building," Murray told the Canadian Press.

"But we were standing around wondering what was going on. And I quickly realized it was an earthquake. And then everybody started shouting out, out, out."

CTV's Ottawa Bureau Chief Robert Fife said CTV staff fled the downtown building where the bureau is located and spilled onto a street, to where hundreds of others had also fled.

CTV's Graham Richardson said there are so far no reports of any damage in Ottawa.

Michelle Honsberger was working on the 10th floor of an Ottawa highrise when the building began to shake.

"Just out of nowhere you feel this incredible shock, it was terrifying, the building was moving back and forth," Honsberger told CTV News Channel Wednesday afternoon. "Everyone immediately jumped out of their cubicles and said, ‘What was that, what's going on?' We didn't even wait for an official alarm. People start evacuating immediately, running down the stairs."

In Huntsville, Ont., where G8 summit preparations are underway, OPP Sgt. Pierre Chamberland said nothing was felt in the area, but said security officials plan for everything, including earthquakes.

In Toronto, workers spilled out of office buildings across the city into a heat wave that had temperatures reaching 37 C with the humidex.

"I was in my office at the time and the floor began to shake and it felt like it was sort of on water," one witness told CTV Toronto. "It was quite disturbing."

The City of Toronto issued a statement Wednesday afternoon saying that after an initial assessment, there appears to be no major damage to city infrastructure. The Toronto Transit Commission and other regional transit services said there was no damage to their facilities and there were no interruptions in service.

In New York City, emergency officials said they are investigating several reports of shaking buildings. Residents in parts of New Jersey and Michigan also reported feeling the tremor.

Eastern Canada quakes

There are two seismic zones in the region, according to the Earthquake Information Center's Bruce Presgrave: the St. Lawrence Valley seismic zone, and a seismic zone that runs up the Ottawa Valley.

According to Presgrave, one of the largest earthquakes ever in North America was a magnitude 7 that hit the Charlevoix, Que. region in 1663.

Other quakes that have hit the region include:

• A 6.5-magnitude tremor just south of Chicoutimi, Que., which shook homes as far away as Toronto on Nov. 25, 1988.
• A 5.6-magnitude tremor that caused considerable damage in both Cornwall, Ont. and Massena, N.Y.
• A 6.2-magnitude tremor about 10 kilometres east of Temiscaming, Que., triggered small landslides close to its epicenter.