A fire that broke out at a construction site at Sick Kids Hospital overnight may have been deliberately set, Toronto police say.

Fire investigators are probing the cause of a blaze that occurred in an unoccupied building that was under construction near Bay and Elm streets.

No injuries were reported. A damage estimate hasn't been released.

Dozens of construction workers who were unaware of the blaze and showed up for work aren't being allowed to enter the site because the investigation at the scene is ongoing.

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