ACTON, Ont. – A precautionary evacuation of residents near a sulphur plant east of Guelph has ended.

Fire chief Brent Marshall says there was a minor explosion and fire at the Holly Industries plant in Acton around 12:30 p.m. on Thursday.

Marshall says the fire has been put out and that no one was injured, adding the explosion was barely noticed by workers.

He says a police evacuation order for area residents downwind of the plant has been lifted.

Marshall says it’s not known how much sulphur was released but that the amount is believed to be small.

He says a cause of the explosion and fire isn’t yet apparent and that investigators could not immediately access the site.

“The situation is very stable now,” Marshall said, adding workers were scarcely aware of the explosion.

“It was almost unnoticeable to them that there had been an explosion going on.”