MONTREAL -- A siren system that was tested on Tuesday and designed to alert Montrealers about any major industrial accident was too weak and not distinctive enough, according to some citizens.

A series of alert sirens echoed from nine factories across the island in a noisy test of the system which would be used to alert the population if there were a leak of toxic products such as ammonia or acid.

"It's not very distinctive," said Shanta, who was walking with two friends along busy Sainte-Catherine Street in the city's Gay Village, a few streets away from the Molson Coors brewery.

The brewery was one of the locations equipped with the system, which is designed to alert citizens who are outside to quickly head inside the nearest building, close all doors and windows and turn off any ventilation system.

"It was almost like a big ambulance was passing by," said Shanta. "We need a big 'oooooh,' " she added, trying to mimic a sound she thought was more powerful.

"We need something that really sets itself apart from all the noises in downtown Montreal."

The sirens were tested for three minutes at each of the factories.

Authorities said the one-hour exercise was aimed at ensuring the sirens were operating properly.

It was also a chance to check the level of preparedness of all teams involved in emergency measures.

If a toxic leak were to occur, the sirens would serve as notice for people outdoors but Donald Picard, who was inside at the time, said the sound should be louder so people indoors would know not to leave.

"I was inside and didn't hear anything -- it was quite discreet," he said, smoking a cigarette down the street from the Molson factory.

"I would say we need something that pierces the ear a little more. It could have been just regular traffic."

In the case of a real leak, parents would also be urged to not go get their children at school because that would put them all in danger.

Listening to music outside could also be problematic.

A young woman walking outside took off an earbud and said, "I had my headphones on so I didn't hear anything."