CANADA (From CBC News) -- Firefighters on Saturday were still trying to put out smouldering material at a Mississauga paper mill, but have scaled back their efforts after a large blaze first began outside the plant on Friday.

Platoon Chief Dan Green of Mississauga Fire and Emergency Services said the department plans to keep trucks at the scene this weekend. Four units, with four firefighters each, will be there until at least Sunday morning, he said.

The blaze at Norampac Inc. broke out just before 5 p.m. Friday when cardboard stored in a lot behind the factory caught fire.

Firefighters battle huge blaze outside Mississauga paper mill

"We can't really declare it out," Green said of the blaze. "We are trying to make sure the fire in the material is out. We have to break apart the bales and then the bales will be removed from the scene by the company. We might be able to wrap up operations by [Sunday] morning."

Two firefighters suffered heat-related injuries on Friday and were treated by paramedics at the scene. The fire department estimates that temperatures in some of the buildings surrounding the fire soared as high as 200 C at its peak.

"These types of events are strenuous in this heat," Green said, adding the fire smells like a campfire and the smell is evident from a distance away.

The fire was contained in the lot before it could spread to any surrounding buildings, including the paper factory, itself.

Const. Bally Saini of Peel Regional Police said Bramalea Road from Highway 407 to Drew Road has been reopened.

Norampac calls itself "Canada's foremost manufacturer of containerboard."