Toronto Hydro first tweeted about the outages around 5:40 p.m. It said that the issue arose from loss of supply from Ontario's biggest electricity distribution company Hydro one.

Hydro One told Reuters that it first experienced an outage at Ellesmere Transmission System which was impacting Toronto Hydro. "Crews are currently working to determine the cause of the outage," it added.

At its peak, about 40,000 customers were impacted, CBC reported, citing the electric utility.

More than an hour later, Toronto Hydro said that all power had been restored without providing the cause of disruption.

Dozens of Hydro One customers took to Twitter to report electricity outages in their area.

Toronto police said the outages affected Scarborough and the Lawrence-Eglinton area.

Toronto Hydro did not respond to Reuters' request for comment.

(Reporting by Shivani Tanna in Bengaluru; Editing by Sandra Maler)