Residents of several Orange County cities have reported smelling an unusual odor in the area on Thursday night.
A chemical stench similar to paint thinner or butane is permeating Costa Mesa, Huntington Beach, Newport Beach and Irvine, according to fire departments in some of those cities.

The source of the odor remains unknown.

Authorities are urging anyone who experiences abnormal symptoms as a result of the odor to call 911.