Police in Saskatoon form task force to crack the sharp rise in auto thefts since the start of the year. (CBC)

Police in Saskatoon and Regina say auto thefts are up this month.

They're blaming the cold snap — and driver inattention. In many instances in both cities the autos are stolen when the driver leaves it running, unlocked, outside a store.

"Half of our most recent thefts are with keys left in the vehicle," said Elizabeth Popowich with the Regina Police. 

There have been eight thefts in the Queen City since December 17, and four involved autos left running and unattended.

In Saskatoon, Kelsie Fraser with the police said that auto thefts were up 12 per cent in the first two weeks of the month -- to 46