Toronto Hydro says about 260 customers remain without power this morning in the city’s east end.

Toronto Hydro spokesperson Jessica Martin said the outage was first reported at around 1 a.m. and affected about 6,000 customers in the area bounded by Bloor Street, Lakeshore Boulevard, Yonge Street and Coxwell Avenue.

As of 4 a.m., Martin said power had been restored to about half of those customers and the outage perimeter had been reduced to Danforth Avenue, Queen Street, the Don Valley Parkway and Coxwell Avenue.

By 10 a.m., power had been restored to the majority of affected customers.

"Our crews determined that the outage was related to protective equipment being tripped. In order to restore power, the protective devices needed to be tested individually. It’s important to note that this type of occurrence is rare, but the system worked as it was supposed to, is protecting customers and the grid from the risk of harm," Toronto Hydro spokesperson Tori Gass said in a written statement released Thursday.

"Without these protective devices, issues — such as a surge — could travel through the system unchecked, causing damage."