MONTREAL -- Hydro-Quebec says it took three hours to completely restore power Tuesday after a massive outage that affected more than a quarter of a million clients in Montreal.

The outage was blamed on human error.

The utility says a cable that was cut at a power station left more than 268,000 Hydro-Quebec customers without electricity.

The outage covered large swaths of the north-central and eastern parts of the city.

A Hydro-Quebec spokesman said electricity was fully restored around noon.

He says it was a gradual process, adding that in some districts the power came back faster than others.

Montreal's transit authority also reported outage-related delays with the city's subway.