A wave of vehicle thefts is occurring in northern Sonoma County, the CHP reported.

Many of the owners are making it easy for thieves by leaving doors unlocked and the ignition key inside, Officer Jon Sloat said.

Ten vehicles have disappeared so far this year from Cloverdale and Geyserville. Typically the area has seven to 15 vehicle thefts a year, said Sloat.

CHP officers suspect a ring of local residents are involved.

Nine times the owners left the key inside and in most of those cases the doors have been unlocked.

Three vehicles disappeared Tuesday, two from Geyserville and one from Cloverdale.

The Chevrolet Equinox, Chevrolet Z-71 truck and Ford Explorer all were unlocked with the ignition keys inside.

Sonoma County Auto Theft Task Force reports indicate about 40 percent of the vehicles stolen in the county had ignition keys left inside, Sloat said.

Sloat asked anyone with information regarding the recent vehicle thefts to call the auto theft task force at (707) 565-1371.