Police in Canada's most populous city have changed how they respond to burglar alarms in an attempt to use officers' time more efficiently, but the new policy has raised safety concerns among some residents.

As of this week, officers in Toronto will only respond to home security alarms when there's either video or audio confirmation that a crime is taking place, an eyewitness at the scene, or multiple zones of the alarm are activated -- meaning that whomever or whatever set off the alarm was able to activate a sensor in multiple areas.

Sgt. Wendy Drummond said the measure was introduced to cut down on time wasted on false alarms, which accounted for 97 per cent of burglar alarms officers responded to in 2016, according to a police report.

"From the time the call was dispatched, to the travel time, to an on-scene investigation and the travel time back, it's quite a lot of time spent on these calls," she said, adding that two officers have to be sent to each home as a safety precaution.

"Currently a lot of the alarms that are going off are because of dead batteries, or animals or pets setting off the sensor."

Drummond said homeowners may have to weigh whether to upgrade their security packages to include video and audio services. She noted that police will still respond if someone hits a duress or panic alarm.

But the new policy raised questions of safety for Christine Arena, who said her Toronto home was broken into in April.

The alarm in her home -- which doesn't have audio or video capabilities -- didn't go off during the incident because of the location of her motion sensor, she said, though the glass at the back of her house was smashed and several items were stolen. The culprits were never caught.

Arena said she finds the new police policy concerning.

"It's a safety issue for me," she said. "If the alarm goes off and police don't respond, then the burglar can just go anywhere in the house. They know that nobody's going to respond to it."

She said she's now considering whether to upgrade her security package to include video and audio service to ensure police respond in case of another break-in.

A spokesman for Bell Canada, which offers home security services through Bell Smart Home, said all of their packages include multiple zone alarms.

He added that 95 per cent of their customers in Toronto subscribe to a guard dispatch service, which sends a private security guard to a home where an alarm has been tripped before contacting police about it.