LOS ANGELES (CBSLA.com) — Dense fog blanketed much of the Southland Thursday morning.

According to the National Weather Service, a dense fog advisory will remain in effect until 9 a.m. in the San Fernando and San Gabriel valleys, Los Angeles County beach cities, downtown Los Angeles, the Hollywood Hills, and parts of Ventura and Santa Barbara counties.

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Forecasters say the fog reduced visibility to a quarter-mile or less, creating dangerous driving conditions along several local freeways, including the 5, 101, and 118 freeways.

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Motorists were urged to reduce speeds, leave extra space between themselves and vehicles in front of them, use only low beams and give themselves extra time to reach their destinations.

Several flights were delayed at Los Angeles International Airport due to low visibility.

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