WALDWICK - Hundreds of utility customers in Bergen County lost power after an explosion at a substation sent flames and thick, black smoke shooting skyward.

It wasn't immediately clear what caused the explosion in Waldwick, which was reported around 10:40 a.m. Sunday.

Several nearby homes were reportedly evacuated as a precaution, but no injuries were reported.

Officials say about 2,000 customers lost their service for a few hours, but power was mostly restored by early Sunday afternoon. A utility spokeswoman said the incident remains under investigation.

Firefighters from Waldwick and several nearby towns were called in to help fight the blaze.