Residents mystified at bright lights flashing over East Bay

Residents in western Contra Costa County were mystified on Monday night after many saw flashing lights in the distance.

The bright lights were actually flaring from a refinery in Rodeo. 

An official from the Phillips 66 San Francisco Refinery said a unit was being started up, and that's why there was flaring.

Flaring is part of a safety process to burn off excess hydrocarbons in the unit, and he said it is not a  health concern.