Leaving your vehicle unlocked could make you a target in Fairfax County, Virginia, where police are now warning residents about a rise in stolen vehicles.

Since the beginning of June, 27 cases of vehicle theft have been reported, including 15 in McLean and four in Franconia, the police said.

Most of the incidents have happened overnight and involve unlocked cars with keys left inside. Garage door openers have also been used to enter houses and steal personal belongings, including other vehicles.

Police said they believe the incidents are connected and the suspects may be armed.

They’re reminding people to always lock your vehicle, secure your home and keep the area well lit. Removing garage door openers from your car is also important.

If you see anything suspicious, contact police.