EDMONTON – Tremors from an earthquake near Fox Creek, Alta. Tuesday were felt as far away as St. Albert, about 280 kilometres away.

The Alberta Energy Regulator confirmed the 4.8-magnitude earthquake, and initially said it was caused by hydraulic fracking. But the AER later backed away, saying it could not confirm the cause, only that it happened in an area where fracking occurs.

The AER has sent a team of investigators to the site, owned by a company called Repsol. The company has ceased operations in the area and will not be allowed to resume fracking until AER gives the go-ahead, according to AER spokesperson Carrie Rosa.

In a statement to Global News, Repsol said it was conducting hydraulic fracturing operations at the site when the earthquake occurred.

“The company is investigating the event, which includes reviewing and analyzing available geological and geophysical data, as well as the onsite seismic monitoring data. Operations will not resume at this location until a full assessment of the event has been completed and approval has been received from the AER,” Brent Anderson, spokesperson with Repsol Oil & Gas Canada, said.

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READ MORE: What is fracking?

Natural Resources Canada’s preliminary findings measured the earthquake at a 4.5 magnitude. NRC said the earthquake happened at 11:27 a.m. (MST) Tuesday about 31 kilometres west of Fox Creek.

NRC said the quake was “lightly felt” in Fox Creek and St. Albert. There were no reports of damage.

“It felt like a large truck driving by,” said Fox Creek operations manager Roy Dell. “Some saw pictures shake on the wall. The Town of Fox Creek is disappointed to hear of another seismic event.”

Cory Sinclair works for the City of St. Albert. He was on the third floor of St. Albert Place when he felt a jolt at around 11:30 a.m.

“I felt a bit of a shake in the building and they were doing a bit of work on the main floor so I thought perhaps it was associated with that, and there was also a door just down the hall so I thought someone has slammed that door,” Sinclair said.

“But afterwards I realized it was in fact a tremor that we had felt.” Tweet This

Sinclair said it was one single shake, not a continued shake.

“Someone had jokingly said that it might have been an earthquake, but we never suspected that at all until one of our colleagues informed us that they had heard report of seismic activity,” Sinclair said.

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Ken Munroe works in St. Albert’s Campbell Business Park. He said he was sitting at his desk, working away, when he felt the quake.

“Suddenly the building shook,” he said. “It was just a bump… It felt like a truck hit the wall or something like that. It was a noticeable enough bump that the monitors shook a little bit.”

Munroe said the shake was very quick and only lasted about two seconds.

“We were sort of thinking, ‘Is it an earthquake? Is it an aftershock? How big is it? Or is it just something falling on the floor?'” he said with a laugh.

“The funny thing is that I said, ‘This feels like an earthquake.’ And, you know, everyone just started laughing at me.” Tweet This

It’s not unusual for earthquakes to be reported in the Fox Creek area. There have been about 200 quakes in the area since December 2013. Alberta averages 30 earthquakes each year.

Last year, there were two 4.4 magnitude earthquakes in the area. Authorities said both quakes were the result of hydraulic fracturing in the oil and gas industry.

READ MORE: Another earthquake in Fox Creek raises concerns over hydraulic fracking

The premier is asking that an Alberta Energy Regulator review of fracking be sped up.

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“My officials have been in touch with the AER to find out exactly what the situation is and where we can get more details on that,” Notley said.

“Generally speaking the AER has been engaged in a review of fracking in particular as it relates to this issue and I’ll be asking them to speed that review up a little bit more to come up with some recommendations that we can consider sooner rather than later.”

The AER announced new requirements in February 2015, after several seismic events in the Fox Creek area. If a seismic event measuring 4.0 or greater occurs within five kilometres of an operator, it must cease operations and inform the AER. If a seismic event between 2.0 and 4.0 occurs, operators must inform AER and invoke their response plan.

The AER reports three events measuring 4.0 or greater in 2015: Jan. 14 (4.23), Jan. 23 (4.61) and June 13 (4.26).

Fox Creek is 263 kilometres northwest of Edmonton.

With files from Slav Kornik, Sarah Kraus, Global News and The Canadian Press.

*Editor’s note: The Alberta Energy Regulator originally told Global News the earthquake was due to hydraulic fracking. However, the AER later said it could not confirm that.