TORONTO -- Ontario's Electrical Safety Authority is ordering the removal of thousands of smart meters from homes across the province after a review found they could pose a fire hazard.

The review was conducted after reports last summer that at least eight meters caught fire in Saskatchewan. The safety agency said the problematic Saskatchewan meters are not used in Ontario, but local utilities have been ordered to discontinue use of a similar model.

"The probability of a serious safety incident in Ontario is low," said David Collie, ESA's president and CEO. "We're issuing our order as a proactive, preventative step. Even if the risk is low it's better to react now and remove that risk altogether."

The ESA found that the model -- a Sensus 3.2 meter with remote disconnect -- is susceptible to arcing within the components if water, moisture or other contaminants get inside. Smart meters are used to measure time-of-use electricity consumption for most residential and small business ratepayers.

Last summer, the Saskatchewan government ordered SaskPower to remove more than 100,000 newer model meters that had already been installed after reports of fires related to the equipment. An investigation in Saskatchewan found that rain water and contaminants getting into the meters appeared to contribute to them failing.

No fires or injuries have been associated with the meters in Ontario though there was one instance of arcing reported, ESA officials said. They would not say in what jurisdiction that occurred.

There are approximately 5,400 of these meters in Ontario, which is a tenth of a per cent of the 4.8 million meters in the province. The bulk of the meters at issue are in the Sarnia area, with hundreds also in the Waterloo, Kitchener and Windsor areas, as well as others scattered throughout the Sudbury, Brant County, Cobourg, Fort Erie, Norfolk, Oakville and Algoma areas.

The ESA has asked local utilities to contact affected customers to let them know their meter will be removed -- with a deadline of March 31 -- and is urging members of the public not to try to remove or alter the meters themselves.

Since the affected meters are only the 3.2 models with a remote disconnect feature, Collie said they may be used in such situations as a trailer park with only seasonal use.

The NDP's Peter Tabuns said his party raised the issue last summer and was told by the energy minister that the Ontario Energy Board said the Saskatchewan meters were not in Ontario.

"(They said) don't worry, be happy, go home," Tabuns said. "Happily the ESA actually looked at the problem, realized it wasn't just one make of meter, that it was a larger problem and they're taking action. The government should have recognized last August that it couldn't just dismiss the problem."

The Progressive Conservatives' energy critic, John Yakabuski, said in a statement that the timing of this action is not acceptable.

"We've been calling for the ministry to take action on this issue since August of 2014," he wrote in a statement. "Ensuring Ontario families are safe should not take six months."

Energy Minister Bob Chiarelli's office said it expects the local utilities to act quickly to comply and notify affected customers. It is up to the individual utilities to work with Sensus to recover all associated costs, a spokeswoman said.

The province's auditor general criticized smart meters in her 2014 annual report, saying the program has so far spent $2 billion -- double its projected cost -- and has not led to the government's electricity conservation goals being met.

The Ontario environmental commissioner has said the gap between peak and off-peak prices needs to be much higher in order to encourage people to conserve.