A three-alarm fire broke out in a house under construction in an upscale neighbourhood in north Toronto on Tuesday morning.

Toronto fire fighters were initially concerned that large propane tanks at the construction site might explode after the home on Yorkminster Road was engulfed shortly before 5:45 a.m.

The home, in a posh neighbourhood south of Highway 401 and east of Yonge Street, near Aldershot Crescent, was under construction and unoccupied at the time.

Emergency services received multiple calls about the blaze, including several from commuters who could see the flames from the highway.

"It was just a big ball of red fire," one neighbour told a reporter early Tuesday morning.

"We were fast asleep and awoke to the sound of police pounding on our door," said another neighbour, who said police told him he had to leave his home.

A number of homes were cleared out over fears that the propane tanks would explode. TTC buses were brought in to keep 50 to 75 neighbours warm until the blaze was brought under control some time after 6 a.m.

Police said it appeared heaters used to keep the construction site warm were to blame for the fire.

Emergency medical crews on the scene said there were no injuries in the blaze. The home, however, suffered more than $300,000 worth of damage according to Toronto Fire.

With a report from CTV Toronto's Michelle Dube