Six unattended cars have been stolen since 2011 began, prompting officials to warn residents against leaving their cars while warming them up. 

Most of the stolen vehicles were taken from apartment complex parking lots, but a few were parked on the street, police said. Two have been recovered.

The thefts occurred on the 800 block of Four Mile Road, the 5700 block of Edsall Road, the 300 block of S. Van Dorn St., the 1600 block of N. Quaker Lane, the 400 block of N. Armistead St., and the 4300 block of Duke St.

All of the vehicles were left running by a driver trying to beat the chilly weather, police said. 

Authorities recommend motorists keep a spare set of keys on them and lock their vehicles with the engine running if possible, park in plain sight and in areas that are well lit. Drivers should never leave valuables in their vehicles, police said.