TORONTO -- No one was hurt in a large explosion at a Hamilton steel plant that sent a dark cloud over the city's east end on Christmas Day, police said.

Hamilton police acting Staff Sgt. Jason Leek said Friday the blast took place in a furnace area of the ArcelorMittal Dofasco facility that was unstaffed at the time, and all employees are accounted for.

The ArcelorMittal Dofasco complex is big and the explosion occurred at least a kilometre from any residences, so no evacuations were required and no injuries have been reported, he said.

Leek said the incident caused "quite a cloud" but it dissipated quickly and police are not aware of any safety or environmental concerns.

"It's one of those things that looked a lot worse than it actually is," he said.

The Ministry of the Environment has been called to investigate, as is required.

The cause of the explosion has not yet been determined.

This report by The Canadian Press was first published Dec. 25, 2020.