DALLAS (August 10, 2012)--Dallas County officials announced Friday they have authorized aerial spraying of insecticide in the hope of killing mosquitoes responsible for a growing outbreak of West Nile virus in North Texas.

Dallas County Judge Clay Jenkins announced Friday that state planes have been requested for spraying the densely populated northern part of Dallas.

He said the planes will be used only if the city of Dallas and the posh Park Cities in the affected area request them.

Jenkins made the announcement after a meeting with county, state and other officials a day after he declared a public health emergency Thursday.

The mosquito-borne virus has led to nine deaths in the county, more than double the previous high of four in 2006.

County officials had resisted aerial spraying, which the county hasn't done since 1966.