TORONTO -- A large and stubborn blaze that broke out at a recycling facility near Toronto's waterfront early Thursday sent a haze of smoke wafting over parts of the city as firefighters worked for hours to put out the flames.

Toronto's fire chief said it could be some time before the blaze, which began just before 1 a.m., was extinguished.

"I wouldn't be surprised if we're here into tomorrow and even the next couple of days," said Matthew Pegg. "There's still a lot of active fire, but it's controlled and the forward progress is stopped."

The blaze broke out at a facility owned by GFL Environmental Inc., located in an area east of the city's downtown core. The company described the facility as a solid waste transfer station, hauling yard and solid waste material recycling site.

No injuries were reported among workers who had been in the building.

The roof of the plant collapsed amid the flames and there was extensive damage throughout the facility, fire officials said.

The area that caught fire housed plastics, cardboard and other materials, but the flames had not reached another part of the building that stores garbage.

By Thursday afternoon, heavy equipment was brought in to remove parts of the building and recycling material so firefighters could access the areas that were still burning, Pegg said.

"The content is far too heavy for our firefighters to move manually -- we need forklifts and backhoes and such to pull it apart safely," he said, adding that it was hard to estimate just how long it would take to entirely put out the flames.

"It really depends how this process of taking it apart and fully suppressing it goes."

A steady rain fell as the fire burned and Pegg said that had helped prevent any embers from flying around.

Residents as far away as northwest Toronto reported smelling smoke from the fire, but Pegg said he didn't believe the smoke plume posed any hazards.

Toronto Mayor John Tory was at the scene Thursday morning and echoed Pegg's comments about the smoke.

"People don't need to be worried about that," Tory told reporters. "There is no good smoke, but this is smoke people just smell. It's widespread across the city, but it doesn't, as best anyone knows at the moment, pose any danger."

The fire chief said it was too early to speculate on what may have caused the fire, adding that a hazardous materials team had been called in to monitor runoff from the fire.

Pegg said much of the water being used to battle the blaze was being supplied by a fire boat just offshore in Lake Ontario.